ASTM D1578
Skein Break Fixture for Yarn Breaking Strength
ASTM D1578 Skein Break Fixture – Universal Grip Data Sheet (PDF)
ASTM D1578 is the standard test method for breaking strength of yarn in skein form. Instead of breaking one strand at a time, a reeled skein of many wraps is looped over two holders and pulled apart until every strand has broken, giving one combined breaking load in a single test. Universal Grip builds the skein break fixture with rounded, polished holders that load every strand evenly without cutting the yarn.
What ASTM D1578 Measures
The test reports skein breaking strength, the total force to break all the strands of the skein, and from it the skein break factor and skein breaking tenacity, which normalize the force by the yarn's linear density. The standard applies to spun yarns, single or plied, of any fiber or blend; it is not suitable for yarns that stretch more than 5 % when the tension rises from 2.5 to 7.5 mN/tex. Three options are defined: 80, 40 or 20 turns on a 1.5 m or 1.5 yd reel broken at 300 mm/min; 50 turns on a 1 m or 1 yd reel broken at 300 mm/min; or 50 turns on a 1 m reel broken in 20 s. The skein test is fast and averages many strands, which makes it a staple of spinning-mill QC and fiber-blend comparisons.
How the ASTM D1578 Test Works
Reel the skein on the specified reel circumference with the specified number of turns (80, 40, 20 or 50 depending on the option).
Loop the skein over the upper and lower holders, keeping the strands parallel and untwisted.
Bring the crosshead to a light pretension so all strands share the load.
Separate the holders at 300 mm/min (12 in/min), or at a rate that breaks the skein in about 20 s for Option 3, until all strands have broken.
Record the maximum force as the skein breaking strength.
Convert 40- and 20-turn results to an 80-turn basis by multiplying by 2 or 4, and calculate the break factor or tenacity from the yarn linear density.
Specimens and Setup
Reel skeins at a uniform, low tension; uneven tension means strands break one by one instead of together and lowers the reading.
Keep the reel circumference, number of turns and option consistent within a comparison; 1 m and 1 yd skeins read a few percent higher than 1.5 yd skeins.
Condition yarn to the standard textile atmosphere before reeling and testing.
Size the load cell to the skein: an 80-turn skein carries 160 strands, so the force is far higher than a single-end test.
The standard also gives the calculations for break factor and tenacity; confirm the number of skeins per sample against your specification.
Universal Grip ASTM D1578 Fixture
Rounded, polished holders prevent yarn cutting
Holders spaced to accept the reeled skein
Even load sharing across all skein strands
Quick skein mounting for high test throughput
Steel construction with polished contact surfaces
5 kN standard capacity; higher capacities on request
Clevis pin or threaded adapter to suit the frame
Applications
Spun yarn production QC
Filament yarn testing
Fiber blend comparison
Textile research laboratories
Related Standards and Products
Send us your specimen dimensions, required capacity and machine connection through our contact page and we will quote an ASTM D1578 skein break fixture. Request a quote
ASTM D1578 FAQ
What is the test speed for ASTM D1578?
300 mm/min (12 in/min) for Options 1 and 2, with 80, 40 or 20 turns on a 1.5 m reel or 50 turns on a 1 m reel. Option 3 uses 50 turns on a 1 m reel broken in 20 seconds.
How is skein strength different from single-end strength?
A skein test breaks all the strands of a reeled loop at once and reports one total force, so it averages many ends in one test. ASTM D2256 breaks one strand at a time and reports individual breaking force and elongation.
Why must the holders be rounded and polished?
The yarn wraps over the holders under load. A sharp or rough surface cuts or abrades the strands at the contact line and the skein fails early at the holder instead of in the free length.
Which yarns can be tested?
Spun yarns, single or plied, of any fiber or blend. The method is not suitable for yarns that stretch more than 5 % when tension rises from 2.5 to 7.5 mN/tex, which rules out many highly elastic filament yarns.