Finetech Engineering

Test Specimen Moulds

Complete range of rubber testing moulds - flat sheet, compression set, hardness button, DIN abrasion, Demattia flex, Ross flex, tensile, and custom
Stainless steel 304 construction - corrosion-resistant, withstands repeated high-temperature curing cycles
Diamond-polished cavities - smooth surface finish for dimensionally accurate, flash-free specimens
Precision dowel pins for cavity alignment - ensures uniform specimen thickness and geometry
ASTM D3182, D395, D2240, D430, DIN 53516, ISO 2393, ISO 815 compliant
Used with the Finetech Hydraulic Press (with heated platens) for compression moulding

Overview

Before you can test rubber, you need rubber test specimens. And before you can cut specimens, you need vulcanised rubber sheets and buttons of the correct thickness, surface quality, and cure state. That is what test specimen moulds do – they create the standardised shapes from which specimens are cut or which are tested directly. As a dedicated rubber test specimen mould manufacturer India, Finetech Engineering manufactures every mould from SS 304 stainless steel with diamond-polished cavities for consistent, standard-compliant specimens.

The mould defines the specimen’s thickness, diameter, surface finish, and dimensional uniformity. A poorly made mould with rough cavities, uneven platen surfaces, or imprecise dimensions produces specimens that fail dimensional checks, give inconsistent test results, and waste compound. A well-made mould – precision-machined from stainless steel with diamond-polished cavities – produces specimens that meet every tolerance specified by the standard, test after test, year after year.

Finetech Engineering, your trusted test specimen mould manufacturer India and rubber testing mould manufacturer India, manufactures the complete range of rubber test specimen moulds. Every mould is made from SS 304 stainless steel, precision-ground to dimensional tolerance, and diamond-polished for a surface finish that releases specimens cleanly without sticking. Because we also manufacture the hydraulic press with heated platens, the specimen cutters, and the testing machines, we supply the entire workflow from raw compound to test result – from one manufacturer.

Which Mould Do You Need? - The Complete Selection Guide

The V-notch is not arbitrary. It serves a precise mechanical function: creating a controlled stress concentration that forces the specimen to fracture at a known point. Without the notch, the impact energy would be distributed across the entire specimen. With a precisely cut notch from the Finetech V notch cutter for impact testing India, the test primarily measures the material’s resistance to crack propagation – the property that matters for real-world durability.

What happens if the notch is wrong:

Mould Type	Specimen Produced	Standard	Cavity Dimensions	Used With (Test Equipment)
Flat Sheet Mould	Vulcanised rubber test sheet (2 mm thick standard)	ASTM D3182, ISO 2393	150 × 150 × 2 mm (or 200 × 200 mm; 1, 2, 4, 6 mm thicknesses)	All tests – sheets are cut into dumbbell, tear, crescent, strip, and other specimens
Compression Set Mould (Type 1)	Cylindrical button, 29 mm dia × 12.5 mm	ASTM D395 Type 1, ISO 815	29.0 ±0.5 mm dia × 12.5 ±0.5 mm	Compression Set Apparatus
Compression Set Mould (Type 2)	Cylindrical button, 13 mm dia × 6.3 mm	ASTM D395 Type 2	13.0 ±0.5 mm dia × 6.3 ±0.3 mm	Compression Set Apparatus
Hardness Button Mould	Flat cylindrical button, ≥29 mm dia × ≥6 mm	ASTM D2240, ISO 868	29+ mm dia × 6+ mm thick (stackable for 12 mm)	Shore A / Shore D Hardness Tester
DIN Abrasion Mould	Cylindrical disc, 16 mm dia × 6–16 mm	DIN 53516, ISO 4649, ASTM D5963	16.0 ±0.2 mm dia × variable thickness	DIN Abrasion Tester
Demattia Flex Mould	Grooved rectangular specimen	ASTM D430, ASTM D813, ISO 132	Per standard geometry with central groove	Demattia Flex Tester
Ross Flex Mould	Rectangular bar with pre-cut (pierced)	ASTM D1052	Per standard geometry	Ross Flex Tester
Tensile Dumbbell Mould	Dumbbell-shaped specimen (Die C or ISO Type 2)	ASTM D412, ISO 37	Die C: 115 mm overall, 6 mm gauge width	UTM (alternative to die-cutting from sheets)
Custom Moulds	Any geometry per customer drawing	Customer specification	As specified	Any test equipment

Mould Types - Detailed Specifications

1. Flat Sheet Mould (ASTM D3182 / ISO 2393)

The flat sheet mould is the most important mould in any rubber testing lab. It produces the vulcanised rubber test sheet from which nearly all other test specimens are cut – dumbbells for tensile, angles for tear, crescents, rectangular strips, and more. ASTM D3182 calls it the “standard laboratory mold” and specifies the procedures for mixing compounds and moulding standard sheets.

Specifications

Parameter	Details
Standard	ASTM D3182, ISO 2393
Cavity Size	150 × 150 mm (standard); 200 × 200 mm (larger option)
Sheet Thickness Options	1.0, 2.0, 4.0, 6.0 mm (2.0 mm is the standard for most rubber tests)
Cavities per Mould	1 or 2 (single-cavity or dual-cavity)
Construction	SS 304 stainless steel
Cavity Finish	Diamond-polished for clean specimen release
Frame	Hinged frame with alignment dowel pins
Flash Grooves	Overflow channels for excess compound

Why the flat sheet mould matters: The 2 mm sheet is the starting point for all rubber tensile specimens (ASTM D412), tear specimens (ASTM D624), hardness specimens (if stacking buttons), and crescent tear specimens. Without a good flat sheet mould, every downstream test is compromised.

2. Compression Set Mould (ASTM D395 / ISO 815)

The compression set mould manufacturer India from Finetech produces the cylindrical button specimens used in compression set testing – the test that determines whether a rubber compound will maintain its sealing force over time. Two sizes are available matching the two specimen types in ASTM D395.

Parameter	Type 1 (Large)	Type 2 (Small)
Standard	ASTM D395 Type 1, ISO 815	ASTM D395 Type 2
Button Diameter	29.0 ±0.5 mm	13.0 ±0.5 mm
Button Height	12.5 ±0.5 mm	6.3 ±0.3 mm
Cavities per Mould	3 or 6 (model-dependent)	6 or 12
Construction	SS 304 stainless steel	SS 304 stainless steel
When to Use	Standard specimen – use when material is available	Small specimen – when material is limited

3. Hardness Button Mould (ASTM D2240 / ISO 868)

The hardness button mould manufacturer India from Finetech produces flat cylindrical specimens for Shore A and Shore D hardness testing. ASTM D2240 requires a specimen at least 6 mm thick with flat, parallel surfaces. The mould produces buttons that meet this requirement directly, without cutting or stacking.

Parameter	Details
Standard	ASTM D2240, ISO 868
Button Diameter	≥29 mm
Button Thickness	6 mm (single) or 12.5 mm (standard)
Cavities	3 or 6 per mould
Construction	SS 304
Surface	Diamond-polished – flat, parallel surfaces essential for accurate hardness readings

Why surface finish matters for hardness: A rough or textured specimen surface produces inaccurate Shore hardness readings because the indenter contacts the high points rather than the true surface. The diamond-polished mould cavity produces specimens with the mirror-flat surfaces that ASTM D2240 requires.

4. DIN Abrasion Mould (DIN 53516 / ISO 4649)

The DIN abrasion mould produces cylindrical specimens (16 mm diameter) for abrasion resistance testing on the DIN abrasion tester. Specimens can also be die-cut from sheets using a 16 mm round cutter, but moulding produces more consistent dimensions and density distribution.

Parameter	Details
Standard	DIN 53516, ISO 4649, ASTM D5963
Cylinder Diameter	16.0 ±0.2 mm
Cylinder Height	6–16 mm (minimum 6 mm for test)
Cavities	3 or 6 per mould
Construction	SS 304

5. Demattia Flex Mould (ASTM D430 / ISO 132)

The Demattia flex mould produces the distinctive grooved rectangular specimens used for flex crack initiation and growth testing. The central groove in the specimen creates the stress concentration where flex cracking begins during repeated cycling on the Demattia flex tester.

Parameter	Details
Standard	ASTM D430, ASTM D813, ISO 132, IS 3400 Part 7 & 8
Specimen Shape	Rectangular bar with central transverse groove
Construction	SS 304, precision-machined groove geometry
Cavities	2 or 4 per mould

6. Ross Flex Mould (ASTM D1052)

The Ross flex mould produces rectangular bar specimens with a pre-pierced hole or slit for the Ross flex (cut growth) test. The test measures how fast a pre-existing cut grows under repeated flexing – critical for footwear sole compounds.

Parameter	Details
Standard	ASTM D1052, IS 3400
Specimen Shape	Rectangular bar with central piercing
Construction	SS 304

7. Tensile Dumbbell Mould (ASTM D412 / ISO 37)

While most labs cut dumbbell specimens from flat sheets using a dumbbell cutting die, some labs prefer to mould dumbbell-shaped specimens directly. The tensile dumbbell mould has dumbbell-shaped cavities (Die C or ISO 37 Type 2 geometry) that produce finished specimens ready for the UTM without any die-cutting step.

This is less common than the sheet-and-die method but is useful for compounds where mould flash at the gauge section must be absolutely minimised, or for R&D labs producing very small batches of test specimens.

8. Custom Moulds

Step 1: Weigh and Load

Weigh the correct amount of rubber compound (slightly more than the cavity volume to allow for flash)
Roll or pre-form the compound to approximately fit the cavity shape
Place the compound into the mould cavity

Step 2: Close and Press

Close the mould frame (hinged lid or top plate)
Place the mould between the heated platens of the Finetech hydraulic press
Apply clamping force – typically 3–5 tonnes for specimen moulds

Step 3: Cure

Set the platen temperature per your curing recipe (typically 140–180°C for most rubber compounds)
Maintain temperature and pressure for the specified cure time (typically 10–30 minutes, per ASTM D3182)
Excess compound flows into the flash grooves

Step 4: Demould

Release the press, open the mould, and remove the vulcanised specimen
Trim any flash from the edges with a sharp blade or scissors
Condition the specimen at 23°C / 50% RH for the required duration before testing

Material and Manufacturing Quality

Feature	Finetech Standard	Why It Matters
Material	SS 304 stainless steel	Resists corrosion from repeated exposure to high temperature, moisture, and rubber chemicals. Carbon steel moulds corrode within months.
Cavity Surface	Diamond-polished	Smooth surface enables clean specimen release without sticking. Rough surfaces trap rubber, damage specimen surface, and produce inaccurate test results.
Dimensional Tolerance	Per applicable ASTM/ISO standard	±0.1–0.2 mm cavity dimensions ensure specimens meet the standard’s thickness and diameter requirements.
Alignment	Precision dowel pins	Ensures top and bottom plates close perfectly aligned. Misalignment produces specimens with uneven thickness across the cross-section.
Flash Grooves	Machined overflow channels	Controls where excess compound escapes. Without flash grooves, excess compound forces the mould open and produces oversized specimens.
Finish	Powder-coated exterior	Professional appearance, corrosion protection on non-contact surfaces.

General Specifications

Parameter	Specification
Construction Material	Stainless Steel 304 (SS 304)
Cavity Finish	Diamond-polished (mirror finish for specimen contact surfaces)
Alignment System	Precision dowel pins (2 or 4 per mould)
Frame Type	Hinged frame with handles (flat sheet moulds) or bolted plate assembly (button moulds)
Temperature Rating	Up to 200°C continuous (suitable for all standard rubber curing temperatures)
Compatible Press	Finetech Hydraulic Press with heated platens
Available Mould Types	Flat sheet, compression set (Type 1 & 2), hardness button, DIN abrasion, Demattia flex, Ross flex, tensile dumbbell, custom
Standards Supported	ASTM D3182, D395, D2240, D430, D813, D1052, ISO 2393, ISO 815, ISO 868, ISO 132, DIN 53516, IS 3400
NABL Certification	Dimensional inspection certificate available for all moulds
Certification	ISO 9001:2015 certified manufacturing

Applications

Preparing vulcanised rubber test sheets for tensile, tear, crescent, hardness, and flex specimen cutting (ASTM D3182)
Moulding compression set buttons for seal and gasket compound evaluation (ASTM D395)
Moulding hardness test buttons for Shore A/D testing (ASTM D2240)
Moulding DIN abrasion cylinders for abrasion resistance testing (DIN 53516)
Moulding Demattia flex specimens for flex crack growth testing (ASTM D430)
Moulding Ross flex specimens for cut growth testing (ASTM D1052)
Preparing standard vulcanised specimens for compound comparison, R&D, and incoming material qualification
Custom specimen geometries for product-specific or customer-specified testing

Industries Served

Rubber manufacturing - seals, gaskets, O-rings, hoses, tyres, footwear, belts
Automotive - rubber component QC and compound development
Plastic compounding - compression moulding of test plaques (ASTM D4703)
Third-party and NABL-accredited testing laboratories
R&D and academic institutions

Why Choose Finetech Engineering Specimen Moulds?

SS 304 stainless steel as standard – rubber test specimen mould manufacturer India quality. Every Finetech mould is manufactured from SS 304 stainless steel – not carbon steel. This matters because specimen moulds operate at 140–180°C in a rubber curing environment with chemical accelerators and sulphur. Carbon steel corrodes, pits, and stains specimens within months. SS 304 lasts for years.

Diamond-polished cavities. The cavity surface is diamond-polished to a mirror finish. Rubber releases cleanly from polished stainless steel without sticking, tearing, or surface damage. This is especially important for hardness buttons where surface flatness directly affects test accuracy.

Moulds + press + cutters + testers from one manufacturer. Finetech manufactures the mould, the hydraulic press with heated platens, the specimen cutting dies, and the testing machines. One supplier for the entire workflow from raw compound to test result. One purchase order. One point of contact.

NABL-traceable dimensional certificates. We provide dimensional inspection certificates verifying cavity dimensions against the applicable standard. This documentation supports NABL accreditation for your rubber testing lab.

Custom moulds within 2–3 weeks. Need a non-standard mould? Send us a drawing or dimensions. We will review, quote, and manufacture within 10–21 working days, depending on complexity.

Related Products

Product	Why Related
Hydraulic Press (with Heated Platens)	Essential – the press provides the clamping force and curing temperature for moulding
Dumbbell Specimen Cutter	Cuts tensile specimens from the flat sheets this mould produces
Tear Specimen Cutter	Cuts tear specimens from flat sheets
Round Specimen Cutter	Alternative to moulds for cutting buttons from thick sheets
Compression Set Apparatus	Uses the buttons produced by the compression set mould
DIN Abrasion Tester	Uses the cylinders produced by the DIN abrasion mould
Shore D Hardness Tester	Uses the buttons produced by the hardness button mould
Demattia Flex Tester	Uses the specimens produced by the Demattia flex mould
Specimen Cutters & Moulds (Full Range)	Browse the complete range of cutters and moulds

Our Products

Request a Free Quote

Customisation available

Common Questions

Frequently Asked Questions

What is a test specimen mould?

A test specimen mould is a precision-machined metal form used to produce standardised rubber or plastic specimens for laboratory testing. You place uncured rubber compound into the mould cavity, close it in a hydraulic press with heated platens, and cure (vulcanise) the rubber at temperature and pressure. After curing, you remove a specimen with exact dimensions, surface finish, and cure state specified by the testing standard.

Which mould does a rubber QC lab need first?

The answer to “which rubber test moulds does a QC lab need” always starts with the flat sheet mould manufacturer India product (ASTM D3182) - it produces the vulcanised rubber test sheet from which you cut all other specimens: dumbbell (tensile), tear, crescent, strip, and hardness. After that, add the compression set mould manufacturer India (ASTM D395) and hardness button mould manufacturer India (ASTM D2240) based on your testing requirements.

Why stainless steel instead of carbon steel?

Specimen moulds are exposed to temperatures of 140–180°C, sulphur-based curing agents, chemical accelerators, and moisture over hundreds of curing cycles. Carbon steel corrodes, pits, and eventually transfers rust stains and surface defects to the specimens. SS 304 stainless steel resists all of these - the mould stays clean and dimensionally accurate for years.

What press do I need for moulding?

You need a hydraulic press with electrically heated platens and a PID temperature controller. The Finetech Hydraulic Press (Manual Operation) with the heated platen option is designed for this purpose. Manual presses and pneumatic presses do not have heated platens and cannot be used for moulding - they are for specimen cutting only.

Can I cut specimens from sheets instead of moulding them individually?

Yes, for many specimen types. The flat sheet mould produces a 150 × 150 mm or 200 × 200 mm sheet from which you die-cut dumbbell, tear, crescent, strip, and even round specimens using the appropriate cutting die. This is the standard workflow for most tensile and tear testing. Individual moulds (compression set, hardness, DIN abrasion, Demattia) are used for specimens where specific thicknesses or shapes cannot be easily cut from a flat sheet.

What is the typical cure time for moulding specimens?

Cure time depends on the rubber compound’s curing recipe. ASTM D3182 provides guidance for standard compounds. Typical cure times range from 10 to 30 minutes at 140–180°C, depending on the compound type and thickness. Your compound datasheet or mixing instructions will specify the exact cure temperature and time.

Do you provide NABL certification for moulds?

Yes. Finetech provides NABL-traceable dimensional inspection certificates for all specimen moulds. The certificate verifies that the cavity dimensions (length, width, thickness, diameter, surface roughness) meet the applicable standard’s tolerances. This documentation is essential for NABL-accredited testing laboratories.