What does Handan Rengong Fastener Manufacturing Co., Ltd manufacture?

Handan Rengong manufactures bolts, nuts, screws, washers, anchors, threaded rods, studs, custom metal parts, and non-standard fasteners for global industrial buyers.

Does Rengong supply custom or non-standard fasteners?

Yes. Rengong supports made-to-drawing fasteners, sample customization, OEM and ODM production, private-label packaging, and factory-coordinated quality control.

What materials and grades are available?

Available options include carbon steel, alloy steel, stainless steel, Q235, 35K, 45#, 40Cr, 35CrMo, 42CrMo, 304, 316, and strength grades 4.8, 8.8, 10.9, and 12.9.

What surface treatments can be supplied?

Surface treatments include zinc plating, hot-dip galvanizing, black oxide, phosphating, nickel plating, Dacromet, Geomet, passivation, polishing, plain finish, and custom coatings.

Washer Types Selection Guide: Flat, Spring, Fender, Tooth and Belleville Washers Compared

Washers Are Small Parts With Big Assembly Impact

Washers help distribute load, protect surfaces, adjust spacing, support locking behavior or provide spring force. A wrong washer can damage the mating surface, reduce clamping stability or create assembly problems even when the bolt and nut are correct.

Custom washers and small fastener parts with bright finish — Washer type, thickness, hardness and coating affect assembly stability and surface protection.

Research Notes: What Better Industry Articles Usually Miss

Many washer articles explain shapes, but procurement teams also need thickness, hardness, coating, burr direction, packing and standard equivalence. This guide connects washer selection to real purchasing and inspection needs.

Covers flat, spring, fender, tooth and Belleville washers in one buying guide.
Adds application notes for load distribution, locking support, surface protection and spring force.
Includes factory RFQ details for custom dimensions, coating and private-label packing.

StandardsDIN125, DIN127, DIN6796, ANSI/ASME and custom drawings.

MaterialsCarbon steel, spring steel, stainless 304/316 and special alloys.

FinishesZinc, black oxide, phosphate, nickel, HDG, plain oil and passivation.

InspectionOD, ID, thickness, hardness, burr, flatness and coating.

Washer Function Comparison

Flat Washer

Load spread

High

Locking

Low

Used to distribute load and protect surfaces under bolt heads or nuts.

Spring / Tooth Washer

Lock support

Good

Surface mark

Check

Used where light anti-loosening support is needed, but surface marking may matter.

Belleville Washer

Spring force

High

Design need

Strict

Used where controlled spring load or compensation is required.

Washer Type Selection Table

Washer type	Main function	Common material	Buyer caution
Flat washer	Load distribution and surface protection	Carbon steel, stainless steel	Confirm OD, ID, thickness and hardness
Spring washer	Light locking support and spring action	Spring steel, stainless steel	Not a universal anti-loosening solution
Fender washer	Large outside diameter support	Carbon steel, stainless steel	Check panel size and surface pressure
Tooth washer	Biting action for electrical or locking support	Spring steel, stainless steel	May damage coating or mating surface
Belleville washer	High spring force in compact space	Spring steel, alloy steel	Load curve and orientation matter

Factory Process Flow

Requirement Review

Confirm load, surface, hole size, standard and washer function.

Material Choice

Select carbon steel, stainless or spring steel by application.

Stamping/Forming

Produce flat, spring, tooth or Belleville geometry.

Heat Treatment

Apply hardness or spring property control when required.

Coating And Packing

Finish, inspect and pack by size, label and batch.

RFQ Checklist For Washer Orders

Send washer type, standard or drawing, inner diameter, outer diameter, thickness, material, hardness, coating, quantity, packing, and whether burr direction, flatness, spring force or load test is required.

Surface protectionFlat washers help reduce damage under bolt heads or nuts.

Load distributionLarger OD spreads force over a wider area.

Spring behaviorBelleville washers need engineering confirmation.

Packing controlSmall washers benefit from labeled bags and cartons.

Factory Video Reference

Use video review together with drawings, inspection photos and packing photos. Short process clips can help confirm material, forming, threading, coating color, packing and final appearance before shipment.

Open Rengong YouTube Channel

Expert Review

Reviewed by Rengong Fastener Engineering Team

This guide is prepared from factory production, inspection, coating, packaging, and export quotation experience at Handan Rengong Fastener Manufacturing Co., Ltd. For critical structural applications, final design should also be confirmed by the project engineer and applicable standard.

FAQ

What washer should be used for general bolted assemblies?

Flat washers are common for load distribution and surface protection, but final choice depends on bolt size, surface, load and drawing requirements.

Are spring washers enough to prevent loosening?

Spring washers can provide light locking support, but they are not a universal solution for severe vibration. Application design should be checked.

Can custom washers be made from drawings?

Yes. Custom washers can be made by drawing if ID, OD, thickness, material, hardness, coating and tolerance are confirmed.

What should be inspected for washers?

Typical checks include inner diameter, outer diameter, thickness, hardness, burr, flatness, coating appearance and packing labels.

Useful External References

External links are kept limited and used only for technical context.

This article is written for procurement decision support. Final design, installation torque and safety factors should follow the project drawing, applicable standard and engineering approval.

Need a price for drawings, samples or bulk orders?

Send material, grade, surface treatment, quantity, drawing or sample photos. We will reply with process suggestions and a factory-direct quotation.

WhatsApp +86 151 8888 1444

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