Keep bolted joints tight and protect the surfaces they clamp
A washer is a small part with a big job: it spreads the clamping load of a bolt or nut, protects the surface underneath and, in the case of locking washers, stops the joint from working loose under vibration. Excel Trading Corporation supplies washers for OEM production, maintenance and heavy industry, including original Nord-Lock wedge-locking washers, NF E 25-511 contact lock washers and NF E 25-513 / NF E 25-514 AFNOR flat washers in SS 304 and SS 316.
Plain and load-spreading washers increase the bearing area under a bolt head or nut. That lowers the surface pressure, so the clamped part is not crushed or marked, oversized or slotted holes are bridged, and the joint keeps its preload. They matter most on soft materials such as aluminium, plastics, wood and thin sheet.
Locking washers solve a different problem: bolts working loose under vibration and dynamic loads. Wedge-locking washers such as Nord-Lock use tension instead of friction to hold the bolt, which makes them far more reliable than spring or toothed washers on vibrating machinery, vehicles, rail, wind and mining equipment.
A washer sits under the bolt head or nut and spreads the clamping load over a larger area. This lowers the surface pressure on the clamped part, so soft materials such as aluminium, plastics and thin sheet are not crushed or marked, oversized or slotted holes are bridged, and the bolt keeps its preload. Locking washers add a second job: they stop the bolt or nut from rotating loose under vibration. Choosing the right washer therefore depends on whether the main problem is surface pressure, hole size or vibration.
A wedge-locking washer, such as Nord-Lock, is a pair of washers with cams on the inside faces and radial teeth on the outside faces. The cam angle is steeper than the thread pitch, so any attempt by the bolt to rotate loose makes the pair expand and increases the tension instead of releasing it. Spring and toothed washers rely on friction and spring force, which can be lost under vibration, and independent tests show they offer little protection against self-loosening. Wedge-locking washers are therefore used on vibrating machinery, vehicles, rail, wind and mining equipment where a loose bolt is not acceptable.
Excel Trading Corporation supplies original Nord-Lock wedge-locking washers (NL standard and NLsp enlarged outer diameter) in steel and stainless steel, NF E 25-511 contact lock washers (serrated conical washers) in series N, M and L, and NF E 25-513 (grade C) and NF E 25-514 (grade A) AFNOR flat washers in series Z, M, L and LL, all three AFNOR types in SS 304 and SS 316, for OEM production, maintenance and heavy industry across India. If you need a washer type, size or material that is not listed on this page, send us the standard, size, material and quantity and we will confirm availability.
Use the Request a Quote button on this website and add the washer type, size, material and quantity, or call +91 7204435253 or email info@exceltrading.in with the same details. If you are buying to a standard such as DIN, ISO or NF, include the standard number so we quote the exact part. We supply OEMs and industrial buyers across India from Bengaluru, and lead time is confirmed with the quote.
