If you make rubber seals, O-rings, or gaskets, this is one of the most important tests in your QC lab. The Finetech compression set apparatus manufacturer India product answers one simple but critical question: after you squeeze a rubber seal flat for 22 hours at 70 degrees, how much of its original shape does it spring back to?
That number is called the compression set. A low number (say, 10%) means the rubber bounced back almost completely – it will keep pressing against the mating surfaces and keep the joint sealed. A high number (say, 60%) means the rubber stayed mostly flat – it has lost its springiness and will eventually leak. This is why every seal and O-ring manufacturer in India tests compression set before releasing a batch.
As a trusted rubber compression set apparatus India manufacturer, Finetech Engineering makes this test simple and accurate. The fixture is a set of stainless steel plates held together by bolts, with precision spacer bars between the plates. You put your rubber specimens between the plates, tighten the bolts until the plates touch the spacers (compressing the rubber to exactly 75% of its original height), and put the whole thing in an oven for the required time. When it comes out, you remove the specimens, wait 30 minutes, and measure how much thickness they recovered. That’s your compression set percentage.
As both an ASTM D395 compression set apparatus manufacturer India and an ISO 815 compression set apparatus manufacturer, Finetech Engineering makes this fixture from stainless steel – not the cheaper chrome-plated carbon steel that many competitors use. Carbon steel rusts inside hot, humid ovens. Stainless steel does not. This is the most important difference between a good compression set fixture manufacturer India and a cheap one: what looks the same on day one starts to corrode and warp after a few months inside an oven, affecting your spacer bar dimensions and giving you wrong results.
Feature | Method A – Constant Force | Method B – Constant Deflection (This Product) |
How it works | You apply a set load (weight) to the specimen and measure how much it squashes under that load. | You compress the specimen to exactly 75% of its height using the precision spacer bars of the ASTM D395 Method B constant deflection fixture India. The spacers control the deflection, not a weight. |
What it measures | How much the rubber creeps (deforms slowly) under a constant load. | How much elastic memory the rubber loses when squeezed to a fixed position – which is exactly how a seal or O-ring is compressed in real life. |
Used in industry? | Less common – mainly for load-bearing rubber mounts and bushings. | Yes – used in more than 90% of all industrial seal and O-ring specifications. This is what your customers almost certainly require from a compression set apparatus manufacturer India. |
Standard | ASTM D395 Method A | ASTM D395 compression set apparatus manufacturer India – Method B. Also ISO 815-1, IS 3400 Part 10, DIN 53517. |
Finetech product? | Not a standard Finetech offering – contact us if you need it. | Yes – this is the Finetech stainless steel compression set fixture India on this page. |
The test uses small cylindrical rubber buttons (like a coin-shaped disc). There are two standard sizes. Both are available from Finetech as a rubber compression set apparatus India package:
Specimen | Size | Standard | When to Use |
Type 1 (Large Button) | 29mm diameter x 12.5mm height | ASTM D395 compression set apparatus manufacturer India Type 1, ISO 815 | The standard specimen – use this when you have enough material available. Most labs use Type 1. |
Type 2 (Small Button) | 13mm diameter x 6.3mm height | ASTM D395 Type 2 | Use when your rubber sheet or moulded part is thin and you cannot get a 12.5mm tall specimen from it. |
O-Ring (Actual Part) | Actual O-ring cross-section | ASTM D1414 | Testing the actual seal instead of a moulded button. Needs a special O-ring fixture – contact Finetech. |
The fixture from your compression set tester manufacturer India goes into an oven at the required temperature. These are the most common test conditions used with the ISO 815 compression set apparatus manufacturer specification:
Condition | Temperature | Duration | When Is This Used? |
Room temperature | 23 deg C | 22 or 70 hours | Basic material characterisation – good starting point for any new compound. |
Standard (most common) | 70 deg C | 22 hours | The most widely specified condition worldwide for general-purpose rubber. If your specification does not state otherwise, use this. This is the default for any rubber compression set apparatus India test. |
Moderate high temperature | 100 deg C | 22 or 70 hours | Automotive and industrial seals that operate at moderate service temperatures. |
High temperature | 125 deg C | 70 hours | Engine gaskets, high-temperature automotive seals. |
Very high temperature | 150 deg C | 70 hours | Extreme-temperature seals – FKM (Viton) and silicone compounds. |
This is the formula every ASTM D395 compression set apparatus manufacturer India and ISO 815 compression set apparatus manufacturer product uses:
Symbol | What It Means | Plain English |
t0 | Original specimen thickness (before compression) | How tall the rubber button was when you started |
ts | Spacer bar thickness | How tall the spacer bars are – they define how much you compress the specimen (75% of t0) |
t2 | Recovered specimen thickness (30 minutes after release) | How tall the rubber button is after you release it and wait 30 minutes |
What the result means:
Parameter | Specification |
Product Name | Compression Set Apparatus Manufacturer India – Constant Deflection Fixture (Compression Set Fixture Manufacturer India, Finetech Engineering) |
Also Known As | Compression Set Tester Manufacturer India, Rubber Compression Set Apparatus India, compression set test jig, constant deflection fixture |
Standards Supported | ASTM D395 Compression Set Apparatus Manufacturer India – Method B | ISO 815 Compression Set Apparatus Manufacturer | IS 3400 Part 10 | DIN 53517 |
Test Method | ASTM D395 Method B Constant Deflection Fixture India – 25% deflection of original specimen height |
Construction | Stainless Steel Compression Set Fixture India – SS plates and spacer bars, corrosion-resistant for oven use up to 200 deg C |
Specimen Sizes | Type 1: 29mm dia x 12.5mm height; Type 2: 13mm dia x 6.3mm height |
Specimens per Fixture | 3 to 6 specimens simultaneously (model-dependent) |
Deflection | 25% compression of original thickness (standard); other deflections available on request |
Spacer Bars | Precision ground stainless steel – defines the compressed thickness exactly |
Compression Plates | Flat, parallel, polished stainless steel surfaces |
Clamping | Bolted assembly ensuring uniform pressure across all specimens |
Temperature Range | Ambient to 200 deg C – the fixture goes inside your oven or humidity chamber |
Location | Compression Set Apparatus Thane Maharashtra – manufactured at our Thane facility |
Certification | ISO 9001:2015 certified manufacturing. NABL-traceable dimensional certification available. |
Step 1: Prepare Your Specimens
Step 2: Load the Fixture
Step 3: Test at Temperature
Step 4: Measure and Calculate
Stainless steel, not chrome-plated carbon steel. Most competitors selling a compression set fixture manufacturer India product use chrome-plated carbon steel. It looks shiny when it is new. After six months inside a hot, humid oven, the chrome starts peeling and the steel rusts. Your spacer bar dimensions change, which means your 25% deflection is no longer accurate, which means your test results are wrong. The Finetech stainless steel compression set fixture India costs a little more upfront and works accurately for years.
Precision spacer bars. The spacer bars in our ASTM D395 Method B constant deflection fixture India are precision ground to tight tolerances. The entire accuracy of your compression set test depends on these spacers being the right height. As a dedicated compression set tester manufacturer India, Finetech does not cut corners here.
Complete package from one manufacturer. As your compression set apparatus manufacturer India and compression set fixture manufacturer India, we also make the moulds (to prepare specimens), the round cutters (to cut specimens from sheets), and the hydraulic press. One supplier, one invoice, everything compatible.
All standards covered. ASTM D395 Method B, ISO 815-1, IS 3400 Part 10, and DIN 53517 – all in one ISO 815 compression set apparatus manufacturer and ASTM D395 compression set apparatus manufacturer India product.
Local manufacturer in Thane. As your compression set apparatus Thane Maharashtra manufacturer, Finetech Engineering is the closest option to Mumbai, Pune, Nashik, and factories across Maharashtra. Faster delivery, easy site visits, no import duties, same-state GST. Our competitors for this product are mostly based in Ghaziabad – choosing Finetech means choosing a local rubber compression set apparatus India manufacturer you can actually visit.
Product | Why You Might Need It |
Compression Set Mould (29mm / 13mm) | For moulding the cylindrical rubber button specimens used in the rubber compression set apparatus India test |
Round Specimen Cutter (29mm / 13mm) | For cutting rubber buttons from vulcanised sheets instead of moulding them |
Hydraulic Press | For pressing the compression set mould to make button specimens |
Humidity Chamber | Maintains the test temperature during the ASTM D395 Method B constant deflection fixture India test. Finetech makes this too. |
DIN Abrasion Tester | Complementary rubber testing – wear resistance alongside compression set tester manufacturer India elastic recovery data |
Universal Testing Machine | Complementary tensile and tear testing of the same rubber compounds |
Specimen Cutters & Moulds (Full Range) | Browse all specimen preparation equipment from Finetech |
