Information on the most widely used ASTM standards within the materials testing industry
ASTM D6775 Standard Test Method for Breaking Strength and Elongation of Textile Webbing, Tape and Braided Material
ASTM D6775 specifies how to determine breaking strength and optionally elongation at a specified force (EASF) of textile webbing, tape, and braided materials, using a split-drum type clamping assembly in a tensile testing machine.
Test Principle
A full-width specimen is clamped at both ends in a CRE-type (Constant-Rate-of-Extension) tensile testing machine using split-drum clamps, then pulled at a controlled speed until rupture.
Breaking strength is recorded as the maximum force at failure.
Elongation is measured from the change in distance between two bench marks at a specified force or at break.
The split‑drum clamp prevents slippage and edge stress concentrations common with flat jaws.
Key formula — Elongation at Specified Force (EASF):

Test Scope:
Applies to textile webbing, tape, braided materials.
Max width: 90 mm (3.5 in.).
Max breaking strength: 89 000 N (20 000 lb).
Test Specimens:
| Parameter | Requirement |
| Specimen form | Full-width piece of webbing / tape / braid (no slitting) |
| Minimum length | ≥ 1.4 m for normal testing |
| If post-abrasion testing | ≥ 2.8 m; cut two specimens per sampling unit — mark one "A" (abraded) and one "U" (unabraded) |
| Sampling | Take a lot sample per applicable material spec; if none exists randomly select five rolls/pieces |
| From each lab unit | Cut 1 specimen (≥1.4 m, full-width). If lot has <5 rolls → randomly select 5 specimens representing all rolls |
| Gage length (clamp center‑to‑center) | 250 ± 10 mm (10 ± 0.5 in.). |
| Bench marks for elongation | 125 ± 1 mm (5 ± 0.05 in.), ≥ 40 mm from clamps. |
| Condition | Specimens must be free of folds, creases, wrinkles; avoid oil/water/grease on handling surfaces |
ASTM D6775 Textile Webbing Test Equipment & Apparatus
Tensile testing of webbing / belt / tapes materials involves the testing of flat strips of high-strength woven material used in various applications ranging from sporting goods to military apparel and seat belts. or high performance aramids (Kevlar) and ultra-high molecular weight polyethylene (Dyneema). The woven design without cut fiber at the edges results in a lightweight and strong product.
Webbing grips are necessary for any webbing or strap type textile material. Some manufacturers may also call this a ribbon , wrapping or a capstan fixture. Basically it is any thin and wide material, tapes can also be tested as well. By wrapping the webbing around the drum one can induce a perfect grip. The coefficient of friction will determine how many times the material must be wrapped around the center cylinder. The working principal of this fixture is to spread the strain over a longer area which reduces the propensity for it to break or slip at the wrong time.
| Tensile Testing Machine | CRE‑type, Recommend UnitedTest brand WDW series; Pulling speed: 75 ± 25 mm/min (3 ± 1 in./min). Force range: breaking force within 15–85% of full scale. |
| Webbing tensile fixture | Split-Drum Type; One upper + one lower split-drum clamp;
Drums are positioned opposite each other: upper drum face → front, lower drum face → back |
Key Test Parameters:
Crosshead speed: 75 ± 25 mm/min.
Gauge length: 250 ± 10 mm.
Bench‑mark length: 125 ± 1 mm.
Invalid result: break within 6 mm (0.25 in.) of clamp nip; sample slippage during tension; value 20% below average.
ASTM D6775 Test Procedure Step-by-Step details:
1, Zero the force-measuring system before running specimens; check/re-zero periodically if drift is seen.
2, Set testing machine:
• Crosshead speed = 75 ± 25 mm/min
• Gauge length = 250 ± 10 mm (center-to-center of split drums)
3, Mount specimen — upper clamp:
• Insert one end centrally and completely between the two halves of the split drum in the upper clamp
• Wrap down around the back of the lower half → up around the upper half so the web comes over the upper clamp front
4, Mount specimen — lower clamp:
• Take the opposite end, loosely wrap around both halves of the lower clamp from the back
• Lift the upper half of the lower split drum and insert the end centrally and completely between the two halves
• Remove as much slack as possible
5, If elongation is required:
• Place two fine-ink bench marks 125 ± 1 mm apart, with neither mark closer than 40 mm (1.5 in.) to either clamp nip
• If a slight pretension is specified in the material spec → advance the lower crosshead until the specified tension shows on the recorder
6, Start tester → pull to rupture
7, If elongation is required: stop the tester at the specified force, measure bench-mark spacing to nearest 1 mm (0.05 in.), restart to rupture, record breaking force
8, Discard & retest if below happen:
• Rupture occurs within 6 mm (0.25 in.) of either clamp nip, OR
• Slippage is evident (force plateaus with abnormally high elongation), OR
• Any individual value falls >20 % below the lot average (attributable to faulty technique) → discard result, test another specimen from same package
9. Calculations & Reporting
Breaking force = read directly from machine indicator, reported to nearest 1 %
Average breaking strength = mean of individuals for the lot, to nearest 1 %
EASF = per the formula above, each specimen to nearest 1.0 %; lot average also reported
Report Must Include: Statement that tests followed ASTM D6775; Material/product description & sampling method; Individual breaking forces & lot average.
Related Test Standard:
| ISO 283 | Textile conveyor belts — Full thickness tensile strength, elongation at break and elongation at the reference load — Test method |
| PIA-TEST METHOD-4108D-2015 | STRENGTH AND ELONGATION, BREAKING; TEXTILE WEBBING, TAPE AND BRAIDED ITEMS |
| GB/T 3690 | Textile conveyor belts—Full thickness tensile strength, elongation at break and elongation at the reference load—Test method |
| KS K 0411 | Test methods for the breaking strength and elongation of fabric webbing, adhesive tape, and woven materials |
Industry Fields / Applications
Popular usage:
Seatbelts are often tested to this standard, as well as any tie downs that may be used in the shipping and transportation industry. Safety straps and military equipment also use this type of woven textile material.
The wrap grip solution is also gaining popularilty amongst the bio-medical sector. Small redesigns of this setup can be used to pull tissues without fear of ripping the specimen at the fixture interface. The drum column distributes the strain over a wider area which reduces local stresses which could propagate a tear.
Webbing is a strong fabric woven as a flat strip or tube of varying width and fibres often used in place of rope. It is a versatile component used in climbing, slacklining, furniture manufacturing, automobile safety, auto racing, towing, parachuting, military apparel, load securing, and many other fields.
| Sector | Typical Examples |
| Military / Defense | Cargo tie-downs, harness webbing, parachute components, MIL-spec webbing (e.g., MIL-W-4088) |
| Aviation / Aerospace | Safety restraints, cargo lashing, interior tie-down tapes |
| Automotive / Transportation | Seat-belt webbing validation (often cross-referenced or adapted from similar methods) |
| Outdoor / Life Safety | Climbing harnesses, fall-arrest lanyards, load-rated straps, fire-service life-safety rope-and-webbing gear |
| Industrial Cargo Control | Ratchet-strap webbing, synthetic lifting slings (rated web slings), tow straps |
| Consumer Durable Goods | Backpack carry-loops, heavy-duty bag webbing, pet restraint systems |
Related products and device
Related Standard
ISO 283 is the core tensile test standard for textile-reinforced conveyor belts. It specifies how to cut a full-thickness test piece from the belt and pull it in uniaxial tension until rupture, to determine the Full-thickness tensile strength, Elongation at break, Elongation at the reference force (load).
ASTM D5035 : Standard Test Method for Breaking Force and Elongation of Textile Fabrics (Strip Method)
ASTM D5035 is the standard test method for determining breaking force (tensile strength) and elongation at break of textile fabrics using the strip method. It defines two core procedures--raveled strip (for woven fabrics) and cut strip (for nonwovens, coated/felted fabrics)--and supports both dry and wet testing.
ASTM D5034 for determining the breaking strength (maximum force a fabric can withstand before rupture) and elongation (amount of stretch under tension) of textile fabrics using the grab test principle. It provides two primary procedures: the grab test and modified grab test, with provisions for both dry and wet testing conditions.
FAQs about ASTM D6775 Test for Textile Webbing, Tape and Braided Materials
Q1, What exactly does ASTM D6775 measure?
A: It measures breaking (rupture) force of narrow textile structures (webbing, tape, braided material) and — when required — the elongation at a specified force (EASF) using two bench marks .
Think of it as: “How much tensile load can this strap/web withstand before it fails, and how far does it stretch at a defined working load?”
Q2, Why does D6775 matter? Why is this test “important”?
A: Because these materials are often load-bearing or life-safety items (harness lanyards, cargo tie-downs, seat belts, military webbing, lifting slings, etc.).
Breaking strength defines the ultimate safety margin.
Elongation at specified force tells you energy absorption and how “dynamic” the strap will behave under load (too little stretch → system shock; too much → excess travel/instability).
Q3, How is ASTM D6775 different from ASTM D5034 (Grab) or D5035 (Strip) for fabrics? Which should I use?
| Standard | What it’s for | Clamping style |
| D6775 | Webbing / tape / braided (narrow goods) | Full-width in split-drum clamps (wrapped, not crushed) |
| D5034 | Broad textile fabrics — grab test(jaws narrower than sample) | Flat fabric grab jaws |
| D5035 | Broad textile fabrics — strip test(cut strip clamped full-width) | Flat fabric strip jaws |
Q4, What’s special about the “split-drum clamp” and why not just use regular flat jaws?
A: Narrow, high-tenacity webbings tend to crush, shear, or slip in flat jaws.
The split-drum works like a capstan: the web wraps around a cylindrical surface and is held by friction + gradual wrap, spreading the load so the failure is forced to occur away from the nip, in the free section (gauge length).
Q5: When should a test result be discarded?
A: Discard and retest if:
Specimen breaks within 6 mm of clamp nip
Obvious slippage occurs
A single value is 20% below the group average
Q6: How many specimens are typically tested?
A: At least 5 specimens per test condition; 2 specimens (abraded/unabraded) if abrasion pre‑treatment is required.
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