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M8 x 1.25p Metric Coarse Cup Head Coach Bolts & Nuts Class 4.6 Galvanised AS1390
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- Parcel – From $8
- Express – From $10
- Click and Collect – 2hrs
Orders over $30
- Parcel – FREE
- Express – From $10
- Click and Collect – 2hrs
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| System of Measurement | Metric |
|---|---|
| Product | Cup Head Bolt & Nut |
| Head Type | Cup Head |
| Size | M8 (8mm) |
| Size & Thread Pitch | M8 x 1.25p Coarse |
| Thread Pitch | 1.25mm |
| Thread | Coarse |
| Thread Direction | Right Hand |
| Corrosion Protection Level | Excellent |
| Class Grade | Low Tensile Class 4.6 |
| Material | Carbon Steel |
| Finish | Galvanised |
| Nuts Included | Yes |
| Length (l) | Select from the dropdown |
| Thread Length (t) | Choose your length to view |
| Product Diameter (d) | 7.78 - 8.00mm |
| Head Diameter (a) | 16.90 - 18.00mm |
| Head Height (h) | 4.00 - 4.80mm |
| Square Under Head Width (as) | 7.42 - 8.58mm |
| Square Under Head Height (s) | 4.00 - 4.80mm |
| Closest size in imperial | 5/16" |
| Standard Made To | AS1390:1997 & AS1112:2000 |
| Brand | Hobson Engineering |
| Alternative Brands | Bremick Fasteners | Brighton Best |
Dimensional data is a guide only. Tolerance differences exist between brands and batches
About Cup Head Coach Bolts
Cup Head Coach Bolts, also known as carriage bolts, are used to attach timber to timber or timber to steel. The low-profile domed head sits flush against the timber face, and the square section directly under the head pulls into the timber as the nut is tightened on the other side. This square section grips the timber and resists turning, eliminating the need for a second spanner on the head. Commonly used in structural framing, outdoor furniture, fencing, decking and retaining walls.
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.
Measure the thread diameter, or the square section directly under the dome - its width matches the bolt size (an M10 cup head has a 10mm square). Our visual guide confirms size, pitch and length.
The nut on a cup head bolt is a standard hex nut. Match your spanner / socket AF (across-flats) to the size it fits - our reference chart covers every metric and imperial size we stock.
Frequently Asked Questions
The square section under the domed head pulls into the timber and resists turning while the nut is tightened from the other side.
The square section grips the timber and resists turning, so a coach bolt only needs one spanner on the nut. A hex bolt typically needs two.
A square washer spreads load on timber and resists pull-through. For full assemblies see our matching washers and nuts.
The specs table directly above this description lists the drive type and across-flats (AF) size for this product.
The domed head has no drive recess. The square section under the head grips the timber and resists turning as the nut is tightened.
See the head marking chart and full strength table on our site for the full conversion table and head markings.
Hot-dip galvanising gives a thick (typically 50 to 85 micron) sacrificial zinc coating bonded metallurgically to the steel base. Decades of corrosion protection in most outdoor and rural environments.
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.
Matching Finishes Always match the finish across the assembly. Hot-dip galvanising adds a much thicker coating than zinc plating, so a zinc-plated nut will not wind onto a galvanised bolt, and a galvanised nut on a zinc-plated bolt will be loose. Pair galvanised bolts with galvanised nuts and washers.
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.
Thread Pitch & Terminology
Thread Pitch (Metric) Metric fasteners measure thread pitch as the distance between thread peaks, expressed in millimetres. Metric also branches into three series: coarse (the default; widest tolerance, easiest to tap), fine (a tighter pitch for higher clamp load or thinner walls), and extra fine (the tightest pitch, used for thin-wall tube, precision instruments, and aerospace fittings where vibration loosening must be minimised). Always match the series as well as the size - a metric fine nut will not engage a metric coarse bolt of the same diameter, and an extra fine nut will not engage either. This product has a 1.25mm coarse pitch, meaning the peaks are 1.25mm apart.
How to Measure
Fastener Length This product has a head that sits on top of the material, so the length is measured from directly under the head to the tip of the thread. The head itself is not included in the size.
Thread Length On a bolt the thread length runs from the start of the unthreaded section (called the shank) to the end of the thread. To view the thread length for this product, select a length above.
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 thread length, 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 | KBC46GCM080020, CMC608020GN, BCHMG080201, 627060, KBC46GCM080025, CMC608025GN, BCHMG080251, 627063, KBC46GCM080030, CMC608030GN, BCHMG080301, 627066, KBC46GCM080040, CMC608040GN, BCHMG080401, 627069, 33MG08040R, KBC46GCM080045, CMC608045GN, BCHMG080451, 627072, 33MG08045R, KBC46GCM080050, CMC608050GN, BCHMG080501, 627075, 33MG08050R, KBC46GCM080060, CMC608060GN, BCHMG080601, 627078, KBC46GCM080065, CMC608065GN, BCHMG080651, 627081, 33MG08065R, KBC46GCM080070, CMC608070GN, BCHMG080701, 627084, 33MG08070R, KBC46GCM080075, CMC608075GN, BCHMG080751, 627087, KBC46GCM080090, CMC608090GN, BCHMG080901, 627090, 33MG08090R, KBC46GCM080100, CMC608100GN, BCHMG081001, 627093, 33MG08100R, KBC46GCM080120, CMC608120GN, BCHMG081201, 627099, 33MG08120R, KBC46GCM080130, CMC608130GN, BCHMG081301, 627102, 33MG08130R, KBC46GCM080140, CMC608140GN, 627105, KBC46GCM080150, CMC608150GN, BCHMG081501, 627108, KBC46GCM080180, CMC608180GN, 627111 |
| UPC | 9314818675352, 9337357030642, 662403160912, 9314818675369, 9337357030659, 662403160936, 9314818675376, 9337357030666, 662403160950, 9314818675383, 9337357030673, 662403160974, 9312862100745, 9314818675383, 9337357030673, 662403160974, 9312862100745, 9314818675390, 9337357030680, 662403161018, 9312862100752, 9314818675406, 9337357030697, 662403161032, 9314818675413, 9337357030703, 662403161056, 9312862100769, 9314818437356, 9337357030710, 662403161070, 9312862100776, 9314818675420, 9337357030727, 662403161094, 9314818675437, 9337357030734, 662403161117, 9312862100783, 9314818675444, 9337357030741, 662403161131, 9312862100790, 9314818675451, 9337357051203, 662403161179, 9312862100806, 9314818675468, 9337357030765, 662403161193, 9312862100813, 9314818437363, 662403161216, 9314818675475, 9337357030772, 662403161230, 9314818675482, 662403161254 |
