Header imageFREE Delivery Header imageAustralian OwnedHeader imageSpend DISCOUNTS

Toggle Nav
Cart 0

SPEND DISCOUNT Up to $99 = 5%, between $100 and $249 =10% and over $250 = 15%

Products

To view our complete range Icon All Categories Quick Order
Abrasives View all
Abrasives
Allthread View all
Allthread
Assortment Kits View all
Assortment Kits
Bolts View all
Bolts
Drilling View all
Drilling
Driving View all
Driving
Furniture Fasteners View all
Furniture Fasteners
Machine Screws View all
Machine Screws
Marine & Hardware View all
Marine & Hardware
Masonry Fixings View all
Masonry Fixings
Nuts View all
Nuts
Nutserts | Rivet Nuts View all
Nutserts | Rivet Nuts
Pins & Clips View all
Pins & Clips
Rivets View all
Rivets
Screws for Decking View all
Screws for Decking
Screws for Metal View all
Screws for Metal
Screws for Timber View all
Screws for Timber
Security Fasteners View all
Security Fasteners
Self Tapping Screws View all
Self Tapping Screws
Silicones & Adhesives View all
Silicones & Adhesives
Socket Allen Screws View all
Socket Allen Screws
Taps & Dies View all
Taps & Dies
Tools View all
Tools
U Bolts View all
U Bolts
Washers View all
Washers
FREE Delivery Click & Collect – Murarrie, Brisbane Same-day dispatch before 1pm Australian owned and operated 25,000+ lines ex-stock
Technical Resources
Menu
Account

Flat Round Washers

Flat Round Washers
How to measure washers
Two ways to confirm before you order - whichever you already know.
1If you know your bolt size

Washers are named by the bolt they fit: an M10 washer suits an M10 bolt. The inside diameter is slightly larger than the bolt so it slides on. Our guide covers every size and washer type we stock.

Open the washer measuring guide ›

Open the washer gauge sizing chart ›

2If you have a washer in hand

Measure the inside diameter (ID), outside diameter (OD) and thickness, as shown in the drawing.

Washer measurement diagram - inside diameter, outside diameter and thickness

We stock over 400 flat round washer variants from M1.6 right through to M30, in every material you'd reasonably want, and ship same day on stocked lines.

MATERIALS AND FINISHES

Mild Steel Zinc Plated — Low-cost, suits internal or protected outdoor use. Bright silver finish.

Mild Steel Galvanised — Hot-dip galvanised for outdoor and treated timber applications. Thicker, more durable coating than zinc plate.

Mild Steel Zinc Yellow — Yellow chromate finish, decorative and corrosion-resistant for protected outdoor use.

Mild Steel Black — Plain black uncoated or black zinc plated, often used where appearance matters.

A2-70 G304 Stainless Steel — The most popular stainless grade. General outdoor, food contact, most chemical environments. Products marked A2, A2-70, 304 or G304 are all the same specification.

A4-70 G316 Marine Grade Stainless — The correct choice within 300 metres of the coast and in food or chemical environments. Largely non-magnetic — A small degree of magnetism is normal and not a sign of the wrong grade.

High Tensile Class 8.8 — For high-load structural applications where standard washers would deform.

A4-80 G316 High Tensile Stainless — High tensile stainless for marine and structural applications.

Solid Brass — Non-magnetic, decorative finish, good corrosion resistance. Often used in electrical and plumbing.

Nylon (Natural White / Black) — Electrical insulation, soft contact protection, weather resistance, chemical resistance.

SUB-RANGES WITHIN FLAT WASHERS

Heavy Round Washers — Thicker washer for higher-load applications.

Mudguard Round Washers — Extra-large OD, originally designed for thin sheet metal like mudguards.

High Tensile Round Washers — Class 8.8 grade for structural use.

Nylon Flat Round Washers — Insulating and chemical-resistant flat washer.

UNDERSTANDING WASHER SIZING

Washer sizing can be confusing because the size reference is the bolt diameter the washer is intended to fit, not the washer's outside diameter. An M6 washer fits an M6 bolt — the actual OD and ID are listed in the product title and table. If in doubt, our Technical Resources page has full sizing charts and DIN/ISO standards.

WHY AUSTRALIA TRUSTS BOLT & NUT

With 15+ years selling fasteners online from Brisbane, we hold over 25,000 stock lines and 200 million pieces — 98.75% of online orders placed before 1pm leave same day. Save more as you buy more — we offer up to 13 price breaks plus 3 spend-tier discounts. Read our customer reviews or get in touch if you need help picking the right flat washer.

View as Grid List

Items 1-40 of 462

Set Descending Direction
Page
per page

Flat washers are the workhorse of any fastener box. They increase the bearing surface of a nut or bolt head, spreading clamping force across a larger area — essential when working with soft materials, oversized or irregular holes, or any surface where the head would otherwise dig in. They also give the nut a smooth surface to press against during tightening.

TECHNICAL RESOURCES

Need help identifying your washer? See our washer measuring guide, or check the washer gauge sizing chart.

Key charts and specification sheets: Metric to Imperial Chart · Specs - Flat Round Washers Imperial Zinc Silver · Specs - Flat Round Washers Imperial Stainless G304

For full sizing data and standards, see our Technical PDFs library.

Filter by :
Filter By
Category
System of Measurement
  1. Metric 274 items
  2. Imperial 188 items
Size
  1. M1.6 (1.6mm) 3 items
  2. M2 (2mm) 6 items
  3. M2.5 (2.5mm) 7 items
  4. M3 (3mm) 12 items
  5. M3.5 (3.5mm) 5 items
  6. M4 (4mm) 14 items
  7. M5 (5mm) 19 items
  8. M6 (6mm) 25 items
  9. M7 (7mm) 1 item
  10. M8 (8mm) 23 items
  11. M10 (10mm) 26 items
  12. M12 (12mm) 23 items
  13. M14 (14mm) 9 items
  14. M16 (16mm) 22 items
  15. M18 (18mm) 7 items
  16. M20 (20mm) 21 items
  17. M22 (22mm) 4 items
  18. M24 (24mm) 15 items
  19. M27 (27mm) 5 items
  20. M30 (30mm) 8 items
  21. M33 (33mm) 4 items
  22. M36 (36mm) 6 items
  23. M39 (39mm) 2 items
  24. M42 (42mm) 2 items
  25. M45 (45mm) 1 item
  26. M48 (48mm) 1 item
  27. M52 (52mm) 1 item
  28. M56 (56mm) 1 item
  29. M64 (64mm) 1 item
  30. 3/32" 1 item
  31. 1/8" 9 items
  32. 5/32" 8 items
  33. 8g (4.20mm) 1 item
  34. 10g (4.80mm) 1 item
  35. 3/16" (#10-24) 24 items
  36. 1/4" 29 items
  37. 5/16" 18 items
  38. 3/8" 26 items
  39. 7/16" 4 items
  40. 1/2" 14 items
  41. 9/16" 4 items
  42. 5/8" 9 items
  43. 3/4" 7 items
  44. 7/8" 6 items
  45. 1" 10 items
  46. 1-1/8" 3 items
  47. 1-1/4" 3 items
  48. 1-3/8" 1 item
  49. 1-1/2" 3 items
  50. 1-3/4" 1 item
  51. 2" 3 items
  52. 2-1/4" 1 item
  53. 2-1/2" 1 item
  54. 3" 1 item
To Suit Fastener Size
  1. M1.6 | 1-72 3 items
  2. M2 | #2 | 9BA 6 items
  3. M2.5 | #3 | 7BA 8 items
  4. M3 | 1/8" | #5 | 6BA 21 items
  5. M3.5 | #6 5 items
  6. M4 | 5/32" | 6g | 7g | 8g | #8 | 4BA 23 items
  7. M5 | 3/16" | 10g | #10 | 2BA 44 items
  8. M6 | 1/4" | 12g | 14g | #12 54 items
  9. M7 1 item
  10. M8 | 5/16" 41 items
  11. M10 26 items
  12. M10 | 3/8" 26 items
  13. 7/16" 4 items
  14. M12 | 1/2" 23 items
  15. 1/2" | 2BA 14 items
  16. M14 | 9/16" 13 items
  17. M16 | 5/8" 31 items
  18. M18 7 items
  19. M20 | 3/4" 28 items
  20. M22 | 7/8" 10 items
  21. M24 25 items
  22. M27 | 1-1/8" 8 items
  23. M30 8 items
  24. M33 | 1-1/4" 7 items
  25. M36 | 1-1/2" 10 items
  26. M39 | 1-5/8" 2 items
  27. M42 2 items
  28. M45 | 1-3/4" 2 items
  29. M48 1 item
  30. M52 | 2" 4 items
  31. M56 | 2-1/4" 2 items
  32. M64 | 2-1/2" 2 items
  33. 3" 1 item
Material / Finish
  1. Black Zinc Plated 5 items
  2. Brass 23 items
  3. Galvanised 28 items
  4. Nylon 76 items
  5. Plain Black Uncoated 8 items
  6. Stainless Steel 214 items
  7. Zinc Silver Plated 89 items
  8. Zinc Yellow Plated 19 items
Class / Grade
  1. A2-70 G304 99 items
  2. A4-70 G316 95 items
  3. High Tensile A4-80 G316 20 items
  4. Low Tensile Grade 2 65 items
  5. Low Tensile Class 4.6 76 items
  6. High Tensile Grade 8 19 items
  7. High Tensile Class 8.8 12 items
Corrosion Protection Level
  1. Ultimate 152 items
  2. Excellent 189 items
  3. Moderate 113 items
  4. Low 8 items
Inside Measurement Range Guide
  1. 1.65 - 1.90mm 3 items
  2. 2.10 - 2.40mm 6 items
  3. 2.60 - 2.90mm 7 items
  4. 2.90 - 3.05mm 1 item
  5. 3.10 - 3.60mm 12 items
  6. 3.60 - 4.00mm 14 items
  7. 4.10 - 4.70mm 23 items
  8. 5.00 - 5.75mm 44 items
  9. 6.10 - 7.10mm 25 items
  10. 6.50 - 7.50mm 29 items
  11. 7.30 - 7.80mm 1 item
  12. 8.20 - 9.30mm 41 items
  13. 9.60 - 10.40mm 2 items
  14. 10.20 - 11.70mm 50 items
  15. 11.30 - 12.60mm 4 items
  16. 12.20 - 14.00mm 37 items
  17. 14.20 - 15.60mm 10 items
  18. 15.60 - 16.60mm 3 items
  19. 16.80 - 18.60mm 31 items
  20. 18.20 - 19.60mm 6 items
  21. 19.20 - 21.10mm 2 items
  22. 20.10 - 22.50mm 27 items
  23. 22.30 - 24.50mm 10 items
  24. 24.50 - 27.50mm 24 items
  25. 27.50 - 29.50mm 5 items
  26. 29.10 - 31.80mm 2 items
  27. 31.00 - 33.00mm 7 items
  28. 33.00 - 36.00mm 10 items
  29. 36.50 - 39.00mm 5 items
  30. 39.00 - 43.00mm 7 items
  31. 44.00 - 46.00mm 2 items
  32. 47.00 - 50.00mm 2 items
  33. 51.00 - 53.00mm 1 item
  34. 53.70 - 56.00mm 4 items
  35. 61.00 - 63.00mm 2 items
  36. 67.00 - 69.50mm 1 item
  37. 69.50 - 72.00mm 1 item
  38. 79.00 - 81.00mm 1 item
Outside Dia. Range Guide
  1. 3.00 - 9.99mm 72 items
  2. 10.00 - 14.99mm 48 items
  3. 15.00 - 19.99mm 75 items
  4. 25.00 - 29.99mm 90 items
  5. 30.00 - 34.99mm 36 items
  6. 35.00 - 39.99mm 35 items
  7. 40.00 - 49.99mm 24 items
  8. 50.00 - 59.99mm 37 items
  9. 60.00 - 69.99mm 21 items
  10. 70.00 - 79.99mm 10 items
  11. 80.00 - 89.99mm 3 items
  12. 90.00 - 99.99mm 3 items
  13. 100.00 - 140.00mm 8 items
Thickness Range Guide
  1. 0.30 - 0.49mm 10 items
  2. 0.50 - 0.99mm 81 items
  3. 1.00 - 1.49mm 83 items
  4. 1.50 - 1.99mm 130 items
  5. 2.00 - 2.49mm 29 items
  6. 2.50 - 2.99mm 57 items
  7. 3.00 - 3.49mm 20 items
  8. 3.50 - 3.99mm 29 items
  9. 4.50 - 4.99mm 6 items
  10. 5.00 - 5.99mm 10 items
  11. 6.00 - 6.99mm 5 items
  12. 7.00 - 7.99mm 2 items
  • card
  • card
  • card
  • card
  • card
  • card
  • card
  • card

YOU'RE ON A SECURE SITE

Copyright © 2026 Bolt & Nut Australia Pty LTD, ABN 45 159 328 604

Magento Website built By dZine-Hub

scroll icon