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M12 (1/2") x 50mm x 50mm x 3mm Galvanised Heavy Square Washers Low Tensile HEC Standard
| BUY MORE. SAVE MORE. | ||||
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| Price for each item | Subtotal | % savings | ||
| Buy 1 | Buy 1 | $7.00 each | $7.00 | - |
| Buy 2 + | Buy 2 - 4 | $5.50 each | $11.00 | 21.43% |
| Buy 5 + | Buy 5 - 9 | $3.40 each | $17.00 | 38.18% |
| Buy 10 + | Buy 10 - 19 | $2.00 each | $20.00 | 41.18% |
| Buy 20 + | Buy 20 - 29 | $1.30 each | $26.00 | 35.00% |
| Buy 30 + | Buy 30 - 49 | $1.10 each | $33.00 | 15.38% |
| Buy 50 + | Buy 50 - 74 | $0.80 each | $40.00 | 27.27% |
| Buy 75 + | Buy 75 - 99 | $0.67 each | $50.25 | 16.25% |
| Buy 100 + | Buy 100 - 199 | $0.60 each | $60.00 | 10.45% |
| Buy 200 + | Buy 200 - 499 | $0.50 each | $100.00 | 16.67% |
| Buy 500 + | Buy 500 - 999 | $0.38 each | $190.00 | 24.00% |
| Buy 1000 + | Buy 1000 - 1999 | $0.34 each | $340.00 | 10.53% |
| Buy 2000 + | Buy 2000 + | $0.32 each | $640.00 | 5.88% |
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In Stock
Other Sizes in Range
Delivery Information
Orders under $30 (Bulky items sent as parcel for FREE)
- Aust Post UNTRACKED Letter – FREE
- Parcel – From $8
- Express – From $10
- Click and Collect – 2hrs
Orders over $30
- Parcel – FREE
- Express – From $10
- Click and Collect – 2hrs
5% Off
10% Off
15% Off
| System of Measurement | Metric |
|---|---|
| Product | Heavy Square Washer |
| Industry Size | M12 x 50 x 50 x 3 |
| Size | M12 (12mm) |
| To Suit Fastener Size | M12 | 1/2" |
| Corrosion Protection Level | Excellent |
| Class Grade | Low Tensile Class 4.6 |
| Material | Mild Steel |
| Finish | Galvanised |
| Inside Dimension (id) | 13.10 - 14.20mm |
| Outside Dimension (od) | 50 x 50mm |
| Thickness (t) | 2.60 - 3.00mm |
| Are they Magnetised? | High |
| Dimensional Data | Provided as a guide, subject to change |
| Standard Made To | HEC Standard |
| Brand | Hobson Engineering |
| Alternative Brands | Bremick Fasteners |
Dimensional data is a guide only. Tolerance differences exist between brands and batches
About Heavy Square Washers
Heavy Square Washers are large-area thick steel washers with a square outline, used to spread bolt clamping load on timber and soft materials where a round washer would pull through. The wider square bearing area resists pull-through on timber framing, retaining walls, deck framing and other softwood structural work. The square shape also resists rotation in the host material. Galvanised for outdoor and treated-timber use, also available in stainless and zinc yellow plated.
Recommended use The standard outdoor finish for timber framing, fencing, decking, retaining walls and treated-timber contact (H3 and H4 treated pine). Decades of corrosion protection in most outdoor and rural environments.
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.
Measure the inside diameter (ID), outside diameter (OD) and thickness, as shown in the drawing.
Frequently Asked Questions
Square washers concentrate clamp force differently from round washers (load is spread across the corners as well as the centre). The wider bearing area resists pull-through on timber framing, retaining walls, deck framing and other softwood structural work. Galvanised for outdoor and treated-timber use.
The washer bore is sized with clearance over the bolt diameter so it slides on without binding. Outside diameter and thickness vary by standard (DIN 125, DIN 433, DIN 9021, HEC) for the same nominal bolt size.
Common flat washer standards: DIN 125 (standard metric), DIN 433 (small OD), DIN 9021 (large OD / fender), HEC Standard (Australian commercial), ASTM F436M (hardened structural). Each defines the inside diameter, outside diameter and thickness for each nominal bolt size.
Always pair the washer material to the bolt for galvanic compatibility: stainless bolt to stainless washer, galvanised bolt to galvanised washer. Mixing creates a corrosion cell in wet service.
Material & Coating
Galvanised Hot-dip galvanised carbon steel. The standard outdoor finish; thick zinc coating gives decades of corrosion resistance. The right choice for trailer chassis, mast and pole mounting, structural pipe clamping and outdoor tank fittings.
Important Performance in permanent coastal applications (within 300 metres of the sea) is reduced. Refer to AGA technical bulletins or contact us for the right grade for severe marine exposure.
Class Metric fasteners are classified as class 2, 4.6, 8.8, 10.9, 12.9, 14.9. See the head marking chart and full strength table.
How to Order the Right Size Washer
Washer sizing Washer sizes can be confusing, so here is the quickest way to find the right one. If you already have a bolt or screw, match the bolt size: an M6 bolt takes an M6 washer, M10 takes M10, and so on. Look for the size at the start of the description (e.g. 'M6 Flat Round Washer').
If you only have a loose washer to match, measure the inside diameter and pick the next size down. The washer's inside is always slightly larger than the matching bolt so it slides on freely. For example, an inside measurement of approximately 6.50mm means you need an M6 washer; 17.25mm means you need an M16 washer.
The outside diameter is measured outside-to-outside. Thickness varies between batches - washers are not precision-made fasteners and slight variations are normal. All published measurements on this site should be used as a guide only.
Need every size? See our full washer gauge sizing chart for the complete SWG range (8g to 24g) in mm and inch.
Resources
For full technical data including key product information, range and a CAD drawing, see our Technical PDFs library.
Convert between metric and imperial sizes, gauge to mm, decimal to fraction and TPI to pitch with our measurement conversion calculators.
Pricing & Delivery
Includes GST, a Tax Invoice and Free Standard Delivery anywhere in Australia.
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Technical data Researched and compiled from numerous industry sources for the sole purpose of providing basic information. All material is advisory only and its use by anyone is entirely voluntary. Reliance on it for any purpose by anyone is at the sole risk of that person, and Bolt and Nut Australia is not responsible for any loss, claim or damages arising therefrom. In developing this information, Bolt and Nut Australia has made a determined effort to present it accurately.
Measurements Sizes are taken from supplier catalogues or hand-measured and should be used as a guide. Minor variation between batches is normal. Stock is sourced from various suppliers, so differences may exist between batches in markings, appearance or finish.
Product Photos & PDF Data Sheets Represent the product type, not exact size. PDFs are a reference guide only. Specifications may change without notice.
If you see any problems with any of our specifications or you require additional information please contact us.
Delivery
Weigh less than 500grams
Exceptions: Tools, Kits, Bulky items = Sent as a parcel with tracking
Small orders that fit into the slot of your Letterbox are sent:
FREE with Aust Post Letter delivery with NO TRACKING and delivery between 4-12 business days
Or
Select a Quicker delivery service
- $7.00 Parcel Delivery 2-7 business days
- From $12.00 Express Delivery 1-4 business days
- From $14.00 StarTrack PREMIUM Express Delivery 1-3 business days
Or
Click & Collect - Warehouse pickup
Unit 9, 93 Rivergate Place, Murarrie, QLDPlace your order online and we will have it ready within 2 hours. Call if required sooner
Pickup times between 8am - 4pm, Monday - Friday
Weigh more than 500grams
Included is orders under $30 but weigh more than 500grams or wont fit in the slot of your letterbox
Including Large and Bulky heavy orders are sent:
FREE as a Parcel Delivery WITH TRACKING and delivery between 2-7 business days
Or
Select an Express delivery service
- From $12.00 Express Delivery 1-4 business days
- From $14.00 StarTrack PREMIUM Express Delivery 1-3 business days
Or
Click & Collect - Warehouse pickup
Unit 9, 93 Rivergate Place, Murarrie, QLDPlace your order online and we will have it ready within 2 hours. Call if required sooner
Pickup times between 8am - 4pm, Monday - Friday
Further delivery information can be found on our Delivery page
Supplier Details
| MPN | WSMSGM12050030, WMSQ612G5030, WSQMG125032, 788116, 27SQG503M12 |
| UPC | 9314818235617, 9337357026195, 662403825408, 9312862083475 |
