Threaded Steel Fasteners Testing(IS 1367 Part 3:2017 — ISO 898-1 Equivalent)
Mechanical property class verification of bolts, screws and studs per IS 1367 (Part 3):2017 — proof load, tensile strength and hardness testing confirming the fastener meets its declared property class.
What is Threaded Steel Fastener Testing?
Threaded steel fasteners — bolts, screws and studs — are classified by property class (e.g. 4.6, 8.8, 10.9, 12.9) under IS 1367 (Part 3):2017, equivalent to ISO 898-1, where the two digits encode the minimum tensile strength and the yield-to-tensile ratio. Using an under-strength fastener in a bolted connection is a common and serious failure mode, making property-class verification essential for structural, machinery and pressure-boundary bolting.
Global Lab verifies fasteners against IS 1367 (Part 3):2017 with a proof load test (confirming the fastener withstands the specified load without permanent elongation), a tensile test to failure (yield strength, tensile strength, elongation), and hardness testing correlated to the declared property class. Results confirm whether the fastener genuinely meets its marked grade or is under-strength/counterfeit stock.
Threaded Steel Fasteners Testing — Site Images
How the Threaded Steel Fasteners Testing is Conducted
- 1
Sample Selection & Marking Check
A representative sample of fasteners is drawn from the batch; head markings (property class, manufacturer) are recorded and checked for plausibility against IS 1367-3. - 2
Proof Load Test
The fastener is loaded to the proof load specified for its property class and held for the required duration, then checked for any permanent elongation. - 3
Tensile Test to Failure
A separate sample (or the same fastener, per the applicable clause) is loaded to failure in a calibrated UTM to determine yield strength, ultimate tensile strength and elongation. - 4
Hardness Testing
Hardness is measured on the fastener head or shank and cross-checked against the hardness range specified for the declared property class. - 5
Reporting
Proof load, tensile and hardness results are compiled into a NABL-accredited report confirming whether the fastener meets its declared property class, issued via Autovity QLMS.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 1367 (Part 3):2017 | Technical Supply Conditions for Threaded Steel Fasteners, Part 3: Mechanical Properties of Bolts, Screws and Studs | Property Class Verification (Equivalent ISO 898-1) | Indian Standard |