Information on the most widely used ASTM standards within the materials testing industry
ASTM D2105, ISO 8513
Application: Compliant fully to ASTM D2105 Standard Test Method for Longitudinal Tensile Properties of Reinforced Thermosetting Plastic Pipe and Reinforced Polymer Mortar Pipe
The UnitedTest ASTM D2105 Test Fixture is purpose-built for longitudinal tensile testing of reinforced thermosetting plastic pipe (RTRP) and reinforced polymer mortar pipe (RPMP). Adopting the internal mandrel and segmented split collet clamping configuration specified in ASTM D2105, this modular fixture ensures uniform circumferential clamping, concentric axial loading and prevents premature pipe crushing at gripping regions. Interchangeable inserts accommodate multiple pipe outer diameters. Widely adopted by pipe manufacturers and third-party labs to acquire reliable tensile strength, modulus and elongation data for quality control, product certification and engineering structural design.
General introduction
UnitedTest | ASTM D2105 Fiberglass Pipe Longitudinal Tensile Test Fixture
UnitedTest ASTM D2105 pipe tensile test fixture is a dedicated clamping assembly designed exclusively for longitudinal axial tensile testing of full-section RTRP / RPMP fiberglass composite pipes.
Conventional flat tensile grips (for ASTM D638 specimens) cannot be used for tubular pipe samples; improper clamping will cause end crushing, pipe slippage, eccentric load and invalid rupture data.
Our fixture adopts the **internal mandrel + outer segmented collet sleeve principle** specified in the official figures of ASTM D2105, eliminating premature failure at clamping zones and ensuring pure axial tension aligned with pipe centerline, fully meeting standard test stipulation for fiberglass pipe longitudinal tensile strength, tensile modulus and elongation measurement.
Core Standard Compliance: ASTM D2105
Suitable Test Specimen: Complete straight cut segments of Reinforced Thermosetting Resin Pipe (RTRP) & Reinforced Polymer Mortar Pipe (RPMP); also supports test specimens with pipe joints.
The fixture grips a straight pipe specimen between the fixed and movable crossheads of a universal testing machine, transferring tensile load through a tapered mandrel + segmented sleeve + reinforcing band assembly that expands inward against the pipe wall. This design ensures self-aligning, uniform load transfer while preventing the crushing or splintering of the pipe ends — the critical failure mode that plagues improvised clamping methods.
Key Features
1. Main Fixture Housing (Upper & Lower Base Assembly)
Precision alloy steel, heat treatment, anti-fatigue structure, reserved mounting holes matching universal tensile testers.
2. Segmented Split Collet Gripping Sleeves
Interchangeable collet inserts marked for different pipe outer diameters (such as E38, E43 as shown on components). Multiple size collets available to cover various nominal pipe diameters.
3. Internal Support Mandrels
Matched one-to-one with each collet size, insert into pipe bore to provide inner support.
4. Connection Adapter Shaft
Top pull rod with pin hole, used to connect fixture to tensile machine upper crosshead; lower fixture can be fixed on machine base.
5. Auxiliary Reinforcing Rings
Optional spare parts for high-strength thick-wall fiberglass pipes to further protect clamping region.
Modular design: Customers only need to replace mandrel + collet inserts to test pipes of different outer diameters, without purchasing a full new fixture set. Reduce laboratory procurement costs.
ASTM D2105 Standard Test Method for Longitudinal Tensile Properties of “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe and Tube
ISO 8513 Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Test methods for the determination of the initial longitudinal tensile strength
100% ASTM D2105 Geometry Compliant
Structural form strictly follows the clamping mechanism drawing defined in ASTM D2105 standard, recognized for third-party laboratory testing & buyer-seller arbitration tests.
Modular Interchangeable Insert System
Exchangeable mandrel & split collets support multiple pipe OD ranges. Flexible for multi-spec pipe batch testing.
Self-Centering & Pure Axial Loading
Built-in concentric alignment structure effectively eliminates eccentric load; guarantee valid stress-strain curve data for modulus calculation.
Anti-Crush Uniform Circumferential Clamping
Inner mandrel + outer split collet dual support system prevents pipe wall squeezing damage, solve the common industry pain point of specimen breaking inside gripping area.
Premium Material & Durability
Main body: 40Cr alloy steel, quenched & tempered; contact clamping surfaces: precision grinding + anti-wear treatment. Long service life under continuous cyclic tensile load.
Wide Compatibility
Can be installed on UnitedTest universal tensile testing machines, and most brands of computer-controlled electromechanical tensile testers. Custom interface adapters available upon request.
Suitable for Both Plain Pipe & Joint Specimens
Support testing intact pipe segments and specimens containing pipe couplings, to verify longitudinal tensile strength of fiberglass pipe joints.
Standard Size Coverage (Basic Series)
Fit nominal pipe diameter up to 150 mm (6 inch) as defined in ASTM D2105.
Customization Service (UnitedTest Advantage):
- Larger diameter fiberglass pipe fixture over 6 inch upon special order
- Custom connecting flanges / pull heads to match customer’s existing tensile tester
- Custom marking on collet inserts according to customer requirements
- Optional surface treatment: natural metal finish / black oxidation anti-rust treatment
Specimen Requirements Supported
- Minimum free length between grips: ≥457 mm (18 inch) as required by ASTM D2105
- Specimen: Straight full cross-section fiberglass pipe cut samples
- Test type: Short-term static longitudinal tension test
The fixture uses a bidirectional self-centering collet clamping system:
1. An internal precision machined mandrel is inserted inside the pipe end to support the pipe inner wall and resist inward crushing force during clamping.
2. The outer multi-segment split collet sleeve evenly wraps the pipe outer circumference. When axial compression is applied on the sleeve, radial uniform clamping force locks the pipe outer surface.
3. The upper & lower fixture bodies connect to universal tensile testing machine crossheads. The whole set ensures concentric alignment between pipe specimen and machine load axis, prevents eccentric tension.
4. Uniform circumferential clamping distributes pressure evenly; avoids local pipe wall collapse, fiber delamination and premature breakage at gripping area, so rupture occurs within the specimen’s free test section as required by ASTM D2105.
1. Fiberglass pipe manufacturers (RTRP / RPMP production factory QC laboratory)
2. Third-party material testing institutes & certification laboratories
3. Engineering design institutes for municipal water supply, sewage, chemical pipeline projects
4. Petrochemical, onshore oil & gas corrosion-resistant pipeline R&D departments
5. Construction & underground composite conduit inspection organizations
6. Raw material research lab for glass fiber & thermosetting resin formulation development
What customers test with this fixture:
Longitudinal tensile strength, tensile modulus of elasticity, elongation at break, failure mode analysis for fiberglass pipe, joint tensile bearing capacity. All mechanical parameters required for pipeline structural engineering calculation.
Main specification:
| Standard compliance | ASTM D2105 |
| Material | High-strength alloy steel, hardened; optional nickel-plated or black oxide finish |
| Maximum load capacity | Up to 100 kN per pair, depending on coupling size |
| Specimen OD range | 0.25 – 6.0 in. (6 – 150 mm) |
| Specimen length (minimum) | 18 in. (45.7 cm) between grips |
| Mounting interface | 1"-12 UNF male threaded stud (standard); optional clevis and reducer couplings |
| Operating temperature | -85 °F to +250 °F (-65 °C to +121 °C) with suitable testing chamber |
| Standard temperature rating | 0 °C to +70 °C (ambient laboratory) |
| System elastic strain | ≤ 1 % of specimen gage strain at full capacity (ASTM 5.1.6 compliant) |
| Weight | ≈10 – 28 kg per pair, depending on size |
| Self-aligning | Yes — pivot-mounted, free to rotate into alignment under load |
| Crush-prevention design | Distributed-pressure segmented sleeve + optional reinforcing band |
Standard
ASTM D2105 Standard Test Method for Longitudinal Tensile Properties of "Fiberglass" (Glass‑Fiber‑Reinforced Thermosetting‑Resin) Pipe and Tube
ASTM D2105 determine the comparative longitudinal tensile properties of a fiberglass pipe specimen by pulling it in axial tension to failure under defined conditioning, temperature, and machine‑crosshead‑speed conditions.
ASTM D638 determining the tensile properties of unreinforced and reinforced plastics using dumbbell-shaped (dogbone) specimens tested under closely controlled conditions of conditioning, temperature, humidity, and crosshead speed. For measuring the tensile mechanical properties of unreinforced and reinforced plastics, including thermoplastics, thermosets, molded plastics, and plastic composites.
Why Choose UnitedTet™ D2105 Fixtures
Full ASTM D2105-25 compliance — engineered to the latest 2025 edition's dimensional and performance requirements.
Modular sizing — one base fixture body covers a wide OD range; only the inexpensive mandrel/sleeve set changes between pipe sizes.
Crush-free gripping — distributed radial pressure eliminates the pipe-end splintering that ruins test results and wastes specimens.
Self-aligning pivot — removes operator alignment error; satisfies ASTM 5.1.3 automatically.
High-strength alloy steel — hardened and finished for long service life under repeated high-load cycling.
Rapid changeover — mandrel/sleeve swap in minutes, maximizing machine uptime.
Global support — backed by United Test's network across 80+ countries, with local distributors and technical service.
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