---
product_id: 104206288
title: "M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20)"
brand: "singularity supplies"
price: "$16.88"
currency: USD
in_stock: true
reviews_count: 11
category: "Singularity Supplies"
url: https://www.desertcart.us/products/104206288-m4-4mm-x-20mm-flat-repair-washer-large-od-stainless
store_origin: US
region: United States of America
---

# Stainless steel durability ISO 965 tolerance standard M4 precision fit M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20)

**Brand:** singularity supplies
**Price:** $16.88
**Availability:** ✅ In Stock

## Summary

> 🔧 Elevate your repairs with precision and style — don’t settle for less!

## Quick Answers

- **What is this?** M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20) by singularity supplies
- **How much does it cost?** $16.88 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/104206288-m4-4mm-x-20mm-flat-repair-washer-large-od-stainless)

## Best For

- singularity supplies enthusiasts

## Why This Product

- Trusted singularity supplies brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Bulk Pack of 20:** Value-packed quantity designed to keep your projects moving without interruption.
- • **Precision M4 Fit:** Engineered for exact 4mm fastener compatibility, ensuring seamless assembly every time.
- • **Large Outer Diameter:** Enhanced surface area for optimal load distribution and secure fastening.
- • **Premium Stainless Steel:** Crafted from A2 stainless steel for superior corrosion resistance and lasting strength.
- • **ISO 965 Standard Tolerance:** Manufactured to strict ISO standards guaranteeing consistent quality and performance.

## Overview

The M4 (4mm x 15mm) Flat Repair Washer (Large OD) is a pack of 20 high-quality A2 stainless steel washers designed to meet ISO 965 tolerance standards. With a large outer diameter for superior load distribution and a glossy finish, these washers provide durable, corrosion-resistant performance ideal for professional-grade repairs and upgrades.

## Description

Product Description Washers Flat Washers: A standard washer with a central hole, used to spread the load on surfaces fastened with screwed fixings. Split Washers: A washer with a split section in the diameter that helps provide resistance to unwanted loosening due to vibration. Wave / Crinkle Washers: A variant of washer that has a wave effect across the diameter of the surface providing greater tension between the surface and the screwed fastener. Locking / Shakeproof Washers: A washer with grooves, teeth, or ridges that grip firmly in to the surfaces to provide a strong resistance against unwanted turning. Finishing / Conical Washers: Provide a more finished appearance when used with the appropriate fasteners by providing a smooth finish to surfaces when using fasteners that would otherwise have the head visible. While still providing extra torsion on the surface. Tab Washer: A flat washer with 1 or 2 additional 'tabs' that can be bent in to place once fitted to lock the washer in to place. Standard (Form A-D) A flat washer with a standard central hole, with the specifications determined by the 'form'. Form A: Normal diameter, normal thickness Form B: Normal diameter, light thickness Form C: Large diameter, normal thickness Form D: Large diameter, light thickness Standard (Form E-G) Form E: Larger diameter, normal thickness Form F: Larger again diameter, normal thickness Form G: Largest diameter, larger thickness. Repair / Large OD / Penny / MudGuard / Fender A flat washer with a particularly large outer diameter (OD) in proportion to its central hole. These are commonly used to spread the load on thin sheet metal but can also be used to make a connection to a hole that has been enlarged by rust or wear. Other Construction (Square Hole): A typical flat washer but with a square central hole, designed to fit square-neck fixings such as "Carriage" or "Coach" bolts more securely. Metric sizes are described for the appropriate (equivalent) bolt as the squared neck should always be relatively sized to the bolt shaft. Square: A typical washer with a circular central hole but a squared outer edge designed to be recessed preventing turning once fitted. Small OD / Cheese: Washers with a standard central hole, but a much thinner outer diameter that can sometimes be entirely hidden by the head of the bolt / screw used. Wave / Crinkle A variant of washer that has a wave effect across the diameter of the surface providing greater tension between the surface and the screwed fastener. Crinkle and wave washers are very similar, and function identically, but crinkle variants tend to be slightly thinner, and with more peaks in the surface than typical wave washers. Split A washer with a split section in the diameter that helps provide resistance to unwanted loosening due to vibration. Tabbed A flat washer with 1 or 2 additional 'tabs' that can be bent in to place once fitted to lock the washer in to place. Conical / Finishing Provide a more finished appearance when used with the appropriate fasteners by providing a smooth finish to surfaces when using fasteners that would otherwise have the head visible. While still providing extra torsion on the surface. How to Measure Materials

Review: Good quality - Used as part of refitting parts to antique cast iron fireplace. Strong and good quality.
Review: More than adequate for most scenarios - Good washers for environments with low acid and low salt etc.

## Features

- Washer Type: Flat
- Material: Stainless Steel
- Measurement: Metric
- Plating: N/A
- Tolerance: ISO 965 Standard

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07N4466Y2 |
| Best Sellers Rank | 30,640 in DIY & Tools ( See Top 100 in DIY & Tools ) 207 in Washers |
| Brand Name | Singularity Supplies |
| Colour | Silver |
| Compatible Groove Diameter | 4 Millimeters |
| Customer Reviews | 4.6 out of 5 stars 1,808 Reviews |
| Exterior Finish | Stainless Steel |
| Exterior finish | Stainless Steel |
| Fastener Size | M4 |
| Fastener Type | Flat |
| Fastener size | M4 |
| Finish Types | Polished |
| Item Diameter | 2 Centimetres |
| Item Dimensions | 12 x 2 x 1 centimetres |
| Item Thickness | 4 Millimetres |
| Item Weight | 60 Grams |
| Item thickness | 4 Millimetres |
| Manufacturer | Singularity Supplies Ltd |
| Manufacturer Part Number | HU-XI-100 |
| Material | Stainless Steel |
| Material Type | Stainless Steel |
| Metal | Stainless Steel |
| Number Of Items | 1 |
| Number of Pieces | 20 |
| Outside Diameter | 2 Centimetres |
| Outside diameter | 2 Centimetres |
| Screw Head Style | Flat |
| Set Name | M4 x 20 (A2) Stainless Steel Flat Washing Machine, Polished, Silver |
| Size | M4 x 20 (A2) |
| Thread Size | M4 |
| Unit Count | 20 count |
| Washer Type | Flat |
| Washer type | Flat |

## Product Details

- **Exterior finish:** Stainless Steel
- **Fastener size:** M4
- **Material:** Stainless Steel
- **Outside diameter:** 12 Centimetres
- **Washer type:** Fender, Flat

## Images

![M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20) - Image 1](https://m.media-amazon.com/images/I/71TKW6-mhhL.jpg)
![M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20) - Image 2](https://m.media-amazon.com/images/I/61Nr8QvcWcL.jpg)
![M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20) - Image 3](https://m.media-amazon.com/images/I/81LZj0nI+WL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Good quality
*by C***E on 9 August 2025*

Used as part of refitting parts to antique cast iron fireplace. Strong and good quality.

### ⭐⭐⭐⭐⭐ More than adequate for most scenarios
*by A***K on 1 January 2026*

Good washers for environments with low acid and low salt etc.

### ⭐⭐⭐⭐⭐ Good
*by R***O on 24 November 2024*

Building up a small stock for hobby projects. The washers are well made and finished and will be used on outside applications in the main as I wanted a bit of stainless steel quality to stop the rust. Cant see any reason why they wont work.

## Frequently Bought Together

- M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20)
- M4 (4mm x 40mm) Phillips Pan Head Machine Screws - Steel (Pack of 20) DIN 7985
- M4 Washers, M4 x 9mm Metal Flat Penny Washers Thickness 0.8mm-A2 304 Stainless Steel Washers (50 Pack), AMLOOPH Large OD Plain Wide Metal Washers, Round Flat Spacer Repair Washer For Screws Bolts

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-06-23*