--- product_id: 104206288 title: "M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20)" brand: "singularity supplies" price: "¥2415" currency: JPY in_stock: true reviews_count: 11 url: https://www.desertcart.jp/products/104206288-m4-4mm-x-20mm-flat-repair-washer-large-od-stainless store_origin: JP region: Japan --- # 20mm large outer diameter M4 precision fit A2 stainless steel durability M4 (4mm x 20mm) Flat Repair Washer (Large OD) - Stainless Steel (A2) (Pack of 20) **Brand:** singularity supplies **Price:** ¥2415 **Availability:** ✅ In Stock ## Summary > 🔧 Elevate your fastening game with precision and polish! ## 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?** ¥2415 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/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 - • **Precision M4 Fit:** Engineered for exact metric compatibility with M4 bolts, ensuring seamless assembly every time. - • **Large 20mm Outer Diameter:** Optimized to distribute load evenly on thin sheet metals, preventing damage and enhancing stability. - • **ISO 965 Standard Tolerance:** Manufactured to strict international standards for consistent quality and reliable performance. - • **Premium A2 Stainless Steel:** Corrosion-resistant polished finish that stands up to wear, rust, and the test of time. - • **Pack of 20 for Bulk Projects:** Ideal for professionals and DIYers alike, providing ample supply for multiple repairs or builds. ## Overview The M4 (4mm x 20mm) Flat Repair Washer by Singularity Supplies is a pack of 20 high-quality, polished A2 stainless steel washers designed with a large outer diameter to evenly spread load on thin materials. Engineered to ISO 965 standards, these washers offer corrosion resistance and precise metric compatibility, making them a reliable choice for professional-grade repairs and projects. ## Description A flat washer with a standard central hole, with the specifications determined by the 'form'. A flat washer with a standard central hole, with the specifications determined by the 'form'. 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. 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. A washer with a split section in the diameter that helps provide resistance to unwanted loosening due to vibration. 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. 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. ## 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 | 77,464 in DIY & Tools (See Top 100 in DIY & Tools) 515 in Washers | | Brand Name | Singularity Supplies | | Colour | Silver | | Compatible Groove Diameter | 4 Millimeters | | Customer Reviews | 4.6 4.6 out of 5 stars (1,807) 4.6 out of 5 stars | | Exterior Finish | Stainless Steel | | Fastener Size | M4 | | Fastener Type | Flat | | Finish Types | Polished | | Item Diameter | 2 Centimetres | | Item Dimensions | 12 x 2 x 1 centimetres | | Item Thickness | 4 Millimetres | | Item Weight | 60 Grams | | Manufacturer | Singularity Supplies Ltd | | Manufacturer Part Number | HU-XI-100 | | Material Type | Stainless Steel | | Metal | Stainless Steel | | Number Of Items | 1 | | Number Of Pieces | 20 | | 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 Compatibility | metric bolts | | 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 Name** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good quality *by on Reviewed in the United Kingdom 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 on Reviewed in the United Kingdom 1 January 2026* Good washers for environments with low acid and low salt etc. ### ⭐⭐⭐⭐⭐ Good quality *by on Reviewed in the United Kingdom 13 February 2024* They are the perfect size for what I needed them for! The holes at the bottom of my washing basket had gotten bigger over the years and the wheels started falling off. I was able to use one of these of each side of the base and now it is as good as new and the wheels don't fall off any more ## 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 --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/104206288-m4-4mm-x-20mm-flat-repair-washer-large-od-stainless](https://www.desertcart.jp/products/104206288-m4-4mm-x-20mm-flat-repair-washer-large-od-stainless) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-08-20*