ASTM A370
Mechanical Test Methods for Steel
Downloads: Standard Test Methods and Definitions for Mechanical Testing of Steel Products - (PDF) · ASTM A370 Tensile Fixture – Universal Grip Data Sheet (PDF)
Written by Chris Thomas, Universal Grip Company · Reviewed by Frank Bertini · Updated October 23, 2026
ASTM A370 is the test-method standard for the mechanical testing of steels, stainless steels and related alloys. It defines how to run tension, bend, hardness and Charpy V-notch impact tests, and its annexes add product-specific rules for bars, tubes, fasteners, wire, strand and reinforcing bar. The current edition is A370-26, which revised A370-24a. It is maintained by ASTM Committee A01, Subcommittee A01.13.
A370 tells you how to test. It does not tell you what values to hit. Minimum yield, tensile strength, elongation, bend diameter and impact energy all come from the product specification that calls A370, such as A36, A572, A615, A106 or A193. Where a product specification differs from A370, the product specification governs. A370 is written in inch-pound units; when you test in SI units, use the metric companion ASTM A1058.
This guide is for mill and fabrication labs, third-party test houses, and QC engineers who sign material certs. It covers specimen sizes, test speeds with worked numbers, how to choose a yield method, a complete worked tension calculation, Charpy specimen and acceptance practice, and an annex-by-annex summary with the grips and fixtures each test needs.
ASTM A370 at a glance
Current edition: A370-26 (revises A370-24a); metric companion ASTM A1058
Materials: carbon, alloy and stainless steels and related alloys
Tests: tension, bend, hardness (Brinell, Rockwell, portable) and Charpy impact
Annexes A1–A10: bar, tubular products, fasteners, round wire, significance of notched-bar impact tests, round-to-flat elongation conversion, multi-wire strand, rounding of test data, reinforcing bar, heat-cycle simulation
Acceptance values: none; they come from the product specification
Standard round tension specimen: 0.500 in. diameter, 2 in. gauge length (4D)
Plate-type specimen: 1½ in. wide, 8 in. or 2 in. gauge length
Sheet-type specimen: 0.500 in. wide, 2 in. gauge length
Speed through yield: up to 1/16 in./min per inch of reduced section, or 10,000–100,000 psi/min
Default yield method: 0.2 % offset for continuous yielding; drop-of-beam, autographic or 0.5 % extension-under-load for a yield point
Charpy specimen: Type A V-notch, 10 × 10 × 55 mm, three specimens per test
Machine verification: ASTM E4; extensometers classified per ASTM E83
Note: Specimen dimensions and speed limits in this guide are from recent A370 editions (2016–2022 texts). They have been stable for years, but confirm them against A370-26 before writing a procedure or accepting material.
What A370 covers, and what it doesn't
A370 exists so that mechanical test results on steel are reproducible and comparable between labs. Its uses are conformance to a material specification, incoming acceptance testing, and evaluating material after service. A result outside the specification can come from service degradation, variation within the material or measurement uncertainty, not only from a manufacturing defect.
Several claims about A370 that circulate online are wrong. A370 does not cover chemical analysis (that is ASTM A751). It does not cover fracture toughness tests such as K_IC or CTOD. It does not set minimum strengths, so it cannot “require higher strengths” than any other method. And it has ten annexes, not five.
Specimen orientation and location
A longitudinal specimen has its axis parallel to the direction of greatest extension during rolling or forging. A transverse specimen is at right angles to it. Radial and tangential orientations apply to some circular forgings. The product specification sets which orientation and where in the product the specimen is taken; A370 supplies the definitions.
Tension test specimens
Full-section specimens
Bars, wire and tubes may be tested in full section. Unless the product specification says otherwise, elongation is measured over an 8 in. (200 mm) gauge length.
Plate-type specimens (material 3/16 in. and thicker)
8 in. gauge: gauge length 8.00 ± 0.01 in.; width 1½ in. (+⅛, −¼ in.); fillet radius ½ in. minimum; reduced section 9 in. minimum; overall length 18 in. minimum
2 in. gauge: gauge length 2.000 ± 0.005 in.; width 1½ in.; reduced section 2¼ in. minimum; overall length 8 in. minimum
Sheet-type specimens (0.005–1 in. thick)
Width 0.500 ± 0.010 in. (12.5 mm)
Gauge length 2.000 ± 0.005 in. (50 mm)
Fillet radius ½ in. minimum; reduced section 2¼ in. minimum
Subsize: ¼ in. wide with a 1.000 ± 0.003 in. gauge length
Round specimens
Standard: 0.500 ± 0.010 in. diameter, 2.00 in. gauge length (4D), fillet radius ⅜ in. minimum, reduced section 2¼ in. minimum
Small-size proportional (4D): 0.350 in. / 1.400 in. gauge; 0.250 in. / 1.000 in.; 0.160 in. / 0.640 in.; 0.113 in. / 0.450 in.
Sizes under 0.250 in. are used only when the material is too small for a larger specimen or by agreement
Ends may be plain, threaded or button-head
Many labs machine rounds to 0.505 in. That is within the 0.500 ± 0.010 in. tolerance and gives a cross-sectional area of almost exactly 0.200 in², so load in lbf × 5 equals stress in psi. It is a lab convenience, not a separate A370 size.
Grip choice follows the end style. Flat plate and sheet specimens and plain-end rounds go in wedge grips with flat or Vee jaws. Threaded and button-head rounds go in shoulder grips or threaded adapters, which keep the load on the axis and avoid jaw breaks.
Speed of testing
A370 states speed as limits on the free-running crosshead rate (or, alternatively, the stress rate). The rules in recent editions:
Up to half the specified yield: any convenient speed.
From half the specified yield through yield: crosshead rate no more than 1/16 in./min per inch of reduced section (or per inch between grips for unreduced specimens). Alternatively, where the machine indicates stress rate, keep it between 10,000 and 100,000 psi/min (70–690 MPa/min).
After yield, to tensile strength: no more than ½ in./min per inch of reduced section.
Minimum speed: not less than one-tenth of the maximum rates above.
Strain-rate control is also permitted as a way of expressing speed; check A370-26 for the current wording.
Do not run a closed-loop machine in load control through yield. When the specimen yields, the controller speeds up the crosshead to keep the load rising, and the yield value comes out high. Use crosshead or strain control through yield.
Worked speed numbers
0.500 in. round, 2¼ in. reduced section: through yield ≤ 2.25 × 1/16 = 0.14 in./min (3.6 mm/min), minimum 0.014 in./min; after yield ≤ 2.25 × ½ = 1.125 in./min (28.6 mm/min), minimum 0.11 in./min
8 in. plate specimen, 9 in. reduced section: through yield ≤ 9 × 1/16 = 0.56 in./min (14.3 mm/min); after yield ≤ 9 × ½ = 4.5 in./min (114 mm/min)
0.505 in. round (0.200 in²) in stress-rate terms: 100,000 psi/min = 20,000 lbf/min maximum and 10,000 psi/min = 2,000 lbf/min minimum
Yield: choosing the right method
A370 distinguishes the yield point, found in steels that yield discontinuously with a sharp drop or plateau, from the yield strength, used for steels that yield gradually. The product specification says which one to report and, often, which method.
Yield point (discontinuous yielding)
The yield point is a stress: the first stress in the material, below the maximum, at which strain increases without an increase in stress. It is not a load. Three methods are allowed:
Drop of the beam or halt of the pointer: note the stress at which the load indicator stops or drops while the crosshead keeps moving
Autographic diagram: take the stress at the top of the knee on the recorded curve
Total extension under load (EUL) of 0.5 % (0.005 in./in.): requires a Class C or better extensometer; valid for a specified yield point of 80 ksi (550 MPa) or less, and a higher extension limit is needed above that
Yield strength (continuous yielding)
Offset method (0.2 % default): draw a line parallel to the elastic part of the curve, offset by 0.2 % strain, and read the stress where it intersects the curve. Use a Class B2 extensometer; smaller offsets may need Class B1.
Extension-under-load method: EUL = YS/E + r, where YS is the specified yield strength, E the modulus and r the limiting plastic strain. A Class B1 extensometer is recommended. Default moduli: 30 × 10⁶ psi for carbon steel, 29 × 10⁶ psi for ferritic stainless, 28 × 10⁶ psi for austenitic stainless.
EUL example: specified yield strength 50 ksi, carbon steel, r = 0.002. EUL = 50,000 ÷ 30,000,000 + 0.002 = 0.00167 + 0.002 = 0.00367 in./in. (0.37 %). Read the stress where total strain reaches 0.37 %.
Both methods need a properly classified extensometer. Our extensometers include clip-on, long-travel and non-contact video models; tell us the gauge length and the E83 class your procedure calls for when you ask for a quote.
Tensile strength, elongation and reduction of area
Tensile strength is the maximum load divided by the original cross-sectional area. On a discontinuous curve where the upper yield point is the highest stress, A370 reports the maximum stress reached after yielding as the tensile strength, unless the purchaser specifies otherwise.
Elongation: manual vs at fracture
Manual elongation is the permanent increase in gauge length after fracture. Fit the broken ends together, measure between the gauge marks, and report the percentage together with the original gauge length. Record to 0.01 in. for gauge lengths of 2 in. or less, and to 0.5 % of the gauge length for longer gauges.
Elongation at fracture is measured with an extensometer: the strain just before the sudden force drop at fracture (for very ductile material, where the force falls below 10 % of maximum). The extensometer gauge length must match the specimen gauge length. Use Class B2 for elongations under 5 %, Class C for 5 % to under 50 %, and Class D for 50 % and over. Manual and extensometer elongation are not interchangeable, so report which one you used.
If fracture occurs outside the middle half of the gauge length, or at a punch mark, the result is accepted if it still meets the minimum. If it does not, discard the test and retest. For an 8 in. gauge, mark punch sets 1 in. apart or a pair 8 in. apart; for a 2 in. gauge, sets 1 in. apart or a pair 2 in. apart.
Reduction of area
Reduction of area = (A₀ − A_f) ÷ A₀ × 100, where A_f is measured at the smallest cross section of the fracture after fitting the ends together.
Worked example: 0.500 in. round specimen
Original area: A₀ = π/4 × 0.500² = 0.19635 in²
Yield strength: load at 0.2 % offset = 13,000 lbf; 13,000 ÷ 0.19635 = 66,208 psi, reported as 66,200 psi (456 MPa)
Tensile strength: maximum load = 15,700 lbf; 15,700 ÷ 0.19635 = 79,959 psi, reported as 80,000 psi (552 MPa) after rounding per Annex A8
Elongation: final gauge length 2.56 in. on a 2.00 in. original; (2.56 − 2.00) ÷ 2.00 × 100 = 28 % in 2 in.
Reduction of area: final diameter 0.320 in.; A_f = π/4 × 0.320² = 0.08042 in²; (0.19635 − 0.08042) ÷ 0.19635 × 100 = 59.0 %
Judge the results against the product specification, not A370: if it requires 50 ksi minimum yield, 65–85 ksi tensile and 22 % elongation in 2 in., this specimen passes all three.
Sizing the machine and grips for A370 tension tests
The test frame and load cell must be verified per ASTM E4 and used only within the verified force range. Size the frame for the strongest material you will actually test, not the specification minimum. Some typical loads:
0.505 in. round of 80 ksi steel: 0.200 in² × 80 ksi = 16 kip (71 kN). A 100 kN benchtop or small floor frame is enough.
1½ × ¾ in. plate specimen at 80 ksi: 1.125 in² × 80 ksi = 90 kip (400 kN). A 600 kN floor-standing frame with heavy wedge or hydraulic grips.
#11 Grade 60 rebar: nominal area 1.56 in²; at a 90 ksi minimum tensile that is about 140 kip (≈ 625 kN), and real bars often break higher. Plan on 1,000 kN.
#14 and #18 Grade 60 rebar: 2.25 in² and 4.00 in² give roughly 900 kN and 1,600 kN at the minimum tensile; the largest bars need a 2,000 kN frame.
Check rebar grade values against our ASTM A615 guide. Our Galdabini floor-standing universal testing machines run up to 2,000 kN for full-section bar and heavy plate, and our hydraulic grips are built for exactly that work, with made-to-order sizes up to 2,000 kN. For a broader walkthrough of rebar tension and bend testing, see our article on rebar and steel testing to A615, A370, E8 and E290.
Bend test
The A370 bend test evaluates ductility. It is a pass/fail test, not a strength measurement: there is no “bend strength” result. The specimen is bent at room temperature through the angle and around the inside diameter (pin or mandrel) set by the product specification, then the convex surface is examined for cracks. Acceptance is visual, against the cracking criteria in the product specification.
Severity depends on the bend angle, the inside diameter relative to thickness and the specimen cross section, as well as orientation, location, chemistry, strength and steel quality. Speed is ordinarily not critical. Specimens may be aged for 24–48 h at room temperature before bending, or the aging may be accelerated in boiling water, oil or an oven.
A370 is not a weld-qualification standard. For bend procedures, it points to ASTM E290 (bend testing for ductility) and ASTM E190 (guided bend testing of welds). Our bend testing fixtures include guided-bend and heavy three-point bend fixtures that mount in a universal testing machine for plate and rebar bend tests.
Hardness testing
A370 covers hardness testing mainly by reference to the ASTM hardness methods. The key points from recent editions:
Brinell (E10): 10 mm tungsten-carbide ball (steel balls are no longer permitted), 3,000 kgf standard load, or 1,500 or 500 kgf for thin or soft material. Dwell 10–15 s. Not recommended above 650 HBW. Keep the indent center at least 2.5 indent diameters from edges and other indents, and remove any decarburized surface first.
Rockwell (E18): HRB uses a 1/16 in. carbide ball with a 100 kgf major load and 10 kgf minor load; HRC uses a diamond indenter at 150 kgf. Superficial scales (15, 30 and 45 N or T) use a 3 kgf minor load.
Portable methods: comparative Brinell (A833), Leeb rebound (A956), ultrasonic contact impedance (A1038) and portable Rockwell or Brinell (E110). The instrument and method must be named in the report.
A370 includes approximate conversion tables between Rockwell, Brinell, Vickers and tensile strength; for example, HRB 100 is roughly 240 HBW and about 116 ksi. These conversions are estimates for carbon and alloy steel. They do not apply to austenitic stainless or cold-drawn wire, and they must not be the only basis for accepting or rejecting material. If tensile strength is specified, run a tension test.
Charpy V-notch impact test
The Charpy test measures absorbed energy, percent shear fracture and lateral expansion. In ferritic steels it shows the transition from ductile to brittle behavior as temperature falls. Product specifications may set a minimum energy at a temperature, a fracture-appearance transition temperature, or a lateral-expansion requirement. The detailed apparatus and geometry follow ASTM E23.
Specimen
Full-size Type A V-notch: 10 × 10 × 55 mm
Notch: 2 mm deep, 45° included angle, 0.25 mm root radius
Orientation (default): longitudinal, with the notch perpendicular to the major surface, taken at the tension-test location unless the product specification says otherwise
Placement: the specimen sits on the anvils with the notch facing away from the striker; the striker hits the face opposite the notch
Note: Charpy specimens are 55 mm long, not 50 mm. And the notch faces away from the pendulum striker, not toward it. Both errors appear in published guides.
Subsize specimens
Subsize specimens are used when flat material is thinner than 7/16 in. (11 mm), or when the expected energy would exceed 80 % of the machine's full-scale capacity. Use the largest size the material allows, keeping at least 0.020 in. (0.5 mm) from the surface. Common subsize widths include 7.5 mm and 5 mm. Subsize acceptance values are reduced in proportion to specimen width using A370's subsize table; check the current table values in A370-26.
Machine, temperature and transfer
A370 describes a typical machine capacity of 220–300 ft·lbf (300–400 J) with a striker velocity of 16–19 ft/s (4.9–5.8 m/s), verified per E23. For tests below room temperature, E23 practice is to hold the specimen within ±1 °C (±2 °F) of the test temperature and break it within 5 s of removal from the conditioning medium; confirm the A370-26 wording for your procedure.
Number of specimens and acceptance
A test is normally three specimens from one coupon or location when the specification sets a minimum average. Eight to twelve specimens are used to plot a full transition curve. The acceptance rule commonly applied under A370 is:
The average of the three must meet the specified minimum average
No more than one specimen may be below the minimum average
No specimen may be below two-thirds of the minimum average
Where a retest is permitted, it is typically one further set of three specimens, and each retest value must meet the minimum average
Confirm the retest and acceptance wording in A370-26 and in the product specification, which can override it. Report lateral expansion (in mils) and percent shear when the specification requires them.
Annexes by product form
A1: Bar products
Bars are tested in full section or with machined specimens. Hot-rolled bars commonly use an 8 in. gauge length; cold-finished bars are commonly tested on a 2 in. gauge. Bend tests follow the product specification. Full-section bar goes in wedge grips with Vee jaws or, for larger diameters, hydraulic grips.
A2: Tubular products
Tubes can be tested longitudinally in full section with snug-fitting metal plugs in the ends, so the grips don't crush the wall, or with longitudinal strip specimens cut from the wall. Large-diameter tube may need transverse specimens. The annex also describes the flattening, reverse flattening, flaring, flanging, reverse bend, ring and crush tests that tube and pipe specifications call up.
A3: Fasteners
Annex A3 covers hardness, proof load, wedge tension and axial tension of full-size bolts, machined specimens and nut proof load. The proof-load length-measurement method (the arbitration method) loads the bolt to its proof load, holds it briefly and checks permanent stretch against a very small limit; the yield-strength method uses a 0.2 % offset. The wedge-test details align with ASTM F606/F606M, which has long used a 10° wedge for bolts through 1 in. and 6° above; check whether A370-26 still carries those numbers or defers to F606. Some fastener specifications, such as ASTM A307, call up F606 directly. Our bolt grips handle wedge and axial bolt tension with threaded inserts and hardened wedge washers.
A4: Round wire
Wire is tested in full section, commonly with a 10 in. gauge length for elongation. Breaks in or at the grips are not reportable. The annex also covers the wrap test. Hardness testing is not recommended on very fine wire.
A5 and A6: Impact notes and elongation conversion
Annex A5 explains what notched-bar impact results mean: transition behavior, notch effects, and why Charpy energies are not design values. Annex A6 gives a method to convert percent elongation measured on round specimens into the equivalent for flat specimens, so results from different specimen types can be compared.
A7: Multi-wire strand
Prestressing strand (for example, A416) needs special grips or inserts to avoid breaks in the jaws, a long extensometer gauge, and yield taken at 1 % extension under load per A416. ASTM still lists this annex in A370-26, while some sources report that the detailed method has moved to ASTM A1061/A1061M; check the current text before citing either. Ask us about strand gripping before you order.
A8: Rounding of test data
Annex A8 sets how yield strength, tensile strength, elongation and reduction of area are rounded before they are compared with specification limits. Use the increments in the current edition rather than rounding by habit.
A9: Steel reinforcing bars
Deformed bars are tested in full section with an 8 in. (200 mm) gauge length, using the nominal area from the bar designation (or unit weight) rather than a measured diameter, because the deformations make a measured diameter unreliable. The yield method follows the product specification. As with A7, ASTM still lists this annex, and some sources report that the method now sits in rebar specifications such as ASTM A615; confirm against current editions.
A10: Heat-cycle simulation
Annex A10 covers furnace simulation of post-weld heat treatment on test coupons.
A370 vs ASTM E8 vs ISO 6892-1
Materials: A370 covers steel products only; ASTM E8 covers all metals; ISO 6892-1 covers all metals.
Tests: A370 covers tension, bend, hardness, Charpy and product annexes; E8 and ISO 6892-1 cover tension only.
Units: A370 is inch-pound, with A1058 for SI; E8/E8M is a dual standard; ISO 6892-1 is SI.
Speed: A370 uses crosshead-rate and stress-rate limits; E8 adds strain-rate control methods; ISO 6892-1 uses strain-rate (Method A) or stress-rate (Method B) ranges.
Specimens: A370 and E8 use a 4D gauge on rounds; ISO 6892-1 uses proportional specimens with k = 5.65 (about 5D).
When it governs: A370 governs whenever a steel product specification calls it. Its tension procedure is largely harmonized with E8.
Results from A370 and ISO 6892-1 are close but not directly interchangeable, mainly because of the different gauge-length ratio, so elongation in particular will differ. Other ISO counterparts that are similar but not identical: ISO 7438 (bend), ISO 6506-1 (Brinell), ISO 6508-1 (Rockwell), ISO 148-1 (Charpy), ISO 898-1 (fasteners) and ISO 15630 (rebar and strand).
Common mistakes
Running load control through yield. The crosshead accelerates and the yield value is inflated.
Exceeding the speed limit on long specimens, or using the short-specimen rate on an 8 in. plate. The limit scales with reduced-section length.
Using the wrong extensometer class. Class B2 for 0.2 % offset, Class C or better for the 0.5 % EUL yield point, Class B1 recommended for EUL yield strength.
Mixing manual and extensometer elongation. They are not interchangeable; report which one you used.
Ignoring the middle-half rule. A fracture outside the middle half that fails the minimum is a retest, not a rejection.
Orienting the Charpy notch toward the striker. The striker hits the face opposite the notch.
Letting the Charpy specimen warm up. A slow transfer from the cooling bath raises the measured energy on the transition curve.
Accepting or rejecting on hardness conversions. Conversions are estimates only.
Reporting a “bend strength.” The A370 bend test is pass/fail on cracking.
Testing to an old edition. A370-26 is current; cite the edition on the cert.
Equipment from Universal Grip for A370 testing
We supply the load train for every A370 test except hardness: frames, grips, fixtures, extensometers and pendulum impact testers.
Floor-standing universal testing machines: Galdabini frames up to 2,000 kN for plate, bar and the largest rebar, plus benchtop frames for small rounds and sheet.
Wedge grips: flat and Vee jaws for plate, sheet, bar and machined rounds, in 100, 150 and 300 kN classes.
Hydraulic grips: 100 and 250 kN standard, with made-to-order units up to 2,000 kN for full-section bar and rebar.
Shoulder grips: for threaded and button-head round specimens.
Bolt grips: wedge and axial tension for Annex A3 fastener testing.
Extensometers: clip-on, long-travel and video extensometers for yield and elongation.
Bend testing fixtures: guided-bend and heavy bend fixtures for plate and rebar.
Impact testers: Galdabini pendulum Charpy testers in several capacities, including 300 J and 450 J, with cooling and notch-preparation accessories.
Tell us the product forms you test, the largest section and strength, and your test volume, and we'll recommend a frame and grip package for your A370 work. Request a quote.
ASTM A370 FAQ
What is ASTM A370?
ASTM A370 is the standard test methods and definitions for mechanical testing of steel products, including stainless steels and related alloys. It covers tension, bend, hardness and Charpy V-notch impact tests, with annexes for bars, tubes, fasteners, wire, strand and reinforcing bar. The current edition is A370-26. It defines how to test; the product specification sets the required values.
Does ASTM A370 set minimum strength values?
No. A370 only describes how to test steel. Minimum yield strength, tensile strength, elongation, bend diameter and impact energy all come from the product specification that calls A370, such as A36, A572, A615, A106 or A193. Where the product specification and A370 disagree on a testing detail, the product specification governs.
What is the difference between ASTM A370 and ASTM E8?
ASTM E8 is the general tension test method for all metals. A370 is specific to steel and adds bend, hardness and Charpy impact tests plus product annexes for bars, tubes, fasteners, wire, strand and rebar. The tension procedures are largely harmonized, but A370 governs whenever a steel product specification calls it, and it uses inch-pound units with A1058 as the metric version.
What is the standard A370 tensile specimen?
For round specimens, A370 uses 0.500 in. diameter with a 2 in. gauge length (4D), with smaller proportional sizes that keep the 4:1 ratio. Plate-type specimens are 1½ in. wide with an 8 in. or 2 in. gauge length, and sheet-type specimens are 0.500 in. wide with a 2 in. gauge length. Bars, wire and tubes may also be tested in full section.
What test speed does ASTM A370 require?
Any convenient speed is allowed up to half the specified yield. From there through yield, the crosshead rate is limited to 1/16 in./min per inch of reduced section, or a stress rate of 10,000–100,000 psi/min. After yield, the limit is ½ in./min per inch of reduced section. Speeds must not drop below one-tenth of these maximum rates.
How is yield strength measured under A370?
For steels that yield gradually, A370 uses the 0.2 % offset method or the extension-under-load method. For steels with a sharp yield point, it allows the drop-of-the-beam method, the autographic diagram or 0.5 % total extension under load. The product specification decides which property and method to report, and each method needs an extensometer of a suitable E83 class.
What is the metric version of ASTM A370?
The metric companion is ASTM A1058, Standard Test Methods for Mechanical Testing of Steel Products—Metric. A370 is written in inch-pound units, and it directs labs to use A1058 when testing is performed in SI units. The two standards cover the same tests, so choose the one that matches the units required by your product specification and customer.
How many Charpy specimens does ASTM A370 require?
A Charpy test normally consists of three specimens taken from one coupon or test location when the product specification sets a minimum average energy. The average must meet the minimum, and individual values are limited relative to it. Eight to twelve specimens are typically used when a full ductile-to-brittle transition curve has to be plotted.
What size is a Charpy V-notch specimen?
A full-size Charpy V-notch specimen is 10 × 10 × 55 mm, with a 2 mm deep, 45° notch and a 0.25 mm root radius. It is placed with the notch facing away from the striker. Subsize specimens, such as 7.5 mm or 5 mm wide, are used for thin material or when the energy would exceed 80 % of machine capacity.
Can I convert hardness to tensile strength under A370?
A370 includes approximate conversion tables between Rockwell, Brinell, Vickers and tensile strength; for example, HRB 100 corresponds to roughly 116 ksi. These conversions are estimates for carbon and alloy steels only. They do not apply to austenitic stainless or cold-drawn wire, and they must not be the sole basis for accepting or rejecting material.
What does ASTM A370 Annex A3 cover?
Annex A3 covers mechanical testing of steel fasteners: hardness, bolt proof load by the length-measurement or yield-strength method, wedge and axial tension of full-size bolts, machined specimens for large sizes, and nut proof load. It aligns closely with ASTM F606/F606M, which many fastener specifications, including A307, reference directly.
What gauge length is used for rebar and hot-rolled bar?
Reinforcing bar is tested in full section over an 8 in. (200 mm) gauge length, using the nominal area for the bar size rather than a measured diameter. Hot-rolled bar also commonly uses an 8 in. gauge length, while cold-finished bar is commonly tested on a 2 in. gauge. The product specification can override these defaults.