Railways
Fasteners for railways
Fasteners for rolling stock, where joints see vibration in service. TUFF® hex head bolts are made in classes 8.8, 10.9 and 12.9 in M8 – M160, with all-metal prevailing torque nuts in M8 – M39 and TUFF interlock (wedge-lock) washer pairs in M8 – M36.
TUFF products for this work
Hex Head BoltDIN 931, ISO 4014, IS 1364-1 · M8 – M160, ¼″ – 4″
Prevailing Torque NutDIN 980, ISO 7042, DIN 980-V · M8 – M39
Interlock WasherWedge-lock washer pair · M8–M36
Lock NutDIN 980, ISO 7042, ISO 10513 · M8 – M39- Castle NutDIN 935, BS 1768, ASME B18.2.2 · M8 – M100
- Cotter PinDIN 94, ISO 1234, IS 549 · Ø1 – 20 mm
Testing and inspection
Every lot is tested before dispatch to the applicable standard and the order's inspection plan, in our in-house laboratory accredited by NABL to ISO/IEC 17025:2017 for the tests in its scope. Lots have been inspected on customer orders by agencies including TÜV SÜD, TÜV NORD, Lloyd's Register, DNV, SGS, BVQI, RITES and EIL.
In an independent test by Element Materials Technology, Singapore (report T24-56832R, November 2024), one TUFF M22 class 10.9 HSFG bolt reached 1,221 MPa tensile strength against the ISO 898-1 minimum of 1,040 MPa. This is one sample; results vary by size, grade and lot, and the test certificate of each supplied lot governs. Read the test summary.
Test certificates
We issue test certificates with every lot. State the certificate type your order needs, for example EN 10204 3.1 or 3.2, in the enquiry.
Shipping terms
FOB, CIF or other terms, as agreed for the order.
Send an enquiry
Send the standard, grade, size, quantity, finish and the certificate type your order needs. Open the enquiry form or write to sales@tuffbolt.com.
Where TUFF fasteners have been used
- RailwaysFasteners for railway locomotives and passenger coaches.
Questions
How does the TUFF Interlock Washer prevent loosening?
The system consists of two matched washers installed as a pair. The inner faces have a cam (ramp) profile with defined geometry. The outer faces have radial serrations that grip the bolt head/nut face and the mating surface.
Can prevailing torque type nuts be reused?
Yes, according to ISO 2320 rules, they are qualified for limited reuse cycles (typically up to 5 times) provided the prevailing torque remains above the minimal threshold specified by the engineering design. However, for highly critical joints, structural engineers recommend fitting new nuts.
Do you supply hex bolts with split pin holes?
Yes. Hex bolts with drilled shanks or split-pin holes are manufactured as per customer drawing. Please specify hole diameter, position, and applicable standard at the time of enquiry.
About the maker
- Fasteners since 1996Pioneer Nuts & Bolts Pvt. Ltd., brand TUFF®. Forging, heat treatment, machining and finishing in-house.
- 50 yearsMetallurgy and heat treatment, since 1976.
- IATF 16949:2016Certified quality management system.
- NABL labIn-house laboratory accredited by NABL to ISO/IEC 17025:2017 for the tests in its scope. Lots tested to the applicable standard.
- Japanese collaborationTechnical collaboration with Japanese fastener companies.
- 150+ testimonialsMore than 150 customer testimonials.