Nuts, Washers and Thread Inserts

Nuts, Washers and Thread Inserts complete the fastening system: a bolt is only as reliable as the nut and washer that hold it. This series includes steel flange nuts with integrated knurled flanges, stainless steel heavy hex nuts in standard and non-standard threads, wire thread inserts that repair or reinforce soft-metal threads, and matched automotive nut, bolt and washer kits. Flange nuts carry a wide bearing surface that spreads load on thin or soft materials and reduces the risk of component damage, so a separate flat washer is no longer needed. Heavy hex nuts provide a larger bearing area and higher strength for structural and marine connections, and are produced to DIN934, GB52, GB6170 and GB6172 [TBC] as well as to customer drawings. Wire thread inserts are coils of diamond-section stainless wire installed into a tapped hole; they convert a weak aluminum thread into a wear-resistant, high-load thread and are the standard repair method for damaged threads in engine and gearbox housings. The automotive kits group bolts, nuts, flat washers, spring washers and stamped gaskets in matched material and coating, so no galvanic couple forms at the joint. Materials are carbon steel (case hardened) and stainless steel SUS304/SUS316; coatings include white zinc, color zinc, black zinc, nickel, polishing and hot-dip galvanizing. Threads are gauged on every batch, flange run-out is controlled, and hardness plus salt-spray results are documented. Kits can be packed per vehicle set, per repair set or in bulk with your own part numbers. Typical applications are automotive assemblies, machinery frames, pipe clamps, furniture, structural steel work and thread repair in castings. Standard sizes run from M4 to M16 [TBC]; special threads, nylon-insert lock nuts and left-hand versions are available on request. When specifying nuts and inserts, three parameters matter most: property class, thread tolerance and the mating material. A class 8 nut on a class 8.8 bolt is normal practice; putting a soft nut on a high-tensile bolt simply moves the failure into the nut. For aluminum and zinc castings, a wire thread insert restores the design intent of a steel thread and should be planned at the design stage rather than after a thread strips on the line. Installation requires the matching STI tap and inserting tool - we supply both so the coil seats at the correct depth, one half to one full thread below the surface. Washers are selected by function: flat washers spread load, spring washers add vibration resistance, and serrated flange faces bite into painted surfaces. Kits are packed per drawing with a parts list, and we can print your part numbers directly on each bag for warehouse scanning.