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79mm (3-1/8") Bi-Metal Cobalt Holesaw Alpha HSV79
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| Price for each item | Subtotal | % savings | ||
| Buy 1 | Buy 1 | $47.00 each | $47.00 | - |
| Buy 2 + | Buy 2 + | $42.00 each | $84.00 | 10.64% |
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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 | Bi-Metal Holesaw |
| Size | M79 (79mm) |
| Material | M42 Cobalt Bi-Metal - 8% Cobalt |
| Maximum Cutting Depth (d) | 48mm |
| Drilling Speed | Refer to packaging |
| Arbor Ordering Code | ARB-2 & 3 (31 - 198mm) |
| Closest size in fraction | 3-1/8" |
| Brand | Alpha |
Dimensional data is a guide only. Tolerance differences exist between brands and batches
About Holesaws and Accessories
Holesaws cut large-diameter clean holes (14mm-114mm+) in steel, stainless, timber and plastic. BNA stocks Bi-Metal Cobalt holesaws plus matching arbors, pilot drills and quick-release hex shanks. The cobalt-edged teeth take heat that a standard HSS holesaw cannot, so the saw cuts faster and lasts longer in stainless and hardened sheet.
Frequently Asked Questions
Cobalt-edged teeth take more heat than a standard HSS holesaw, so the saw cuts faster and lasts longer in stainless and hardened sheet. The cup body collects the slug as it cuts. Sizes from 14mm to 114mm+. Standard for electrical cabinet entries, pipe penetrations and any large bolt hole.
BNA stocks Quick Release Hex Shank Holesaw Arbors and matching HSS Pilot Drills. Pick the arbor sized for your holesaw, and replace the pilot drill when it snaps. The holesaw itself usually outlasts several pilots.
For pipe and conduit penetrations, check the actual OD (not the nominal pipe size) and add 1mm-2mm for clearance. For electrical glands, the manufacturer prints the recommended hole size on the box.
Holesaw RPMs are roughly half what a twist drill at the same diameter would run at. The cup teeth take a much longer cut path per revolution and overheat quickly. Withdraw every 5mm-10mm of cut to clear chips out of the cup, otherwise the slug binds and stalls the drill. A few drops of cutting fluid keeps the teeth sharp longer.
Standard HSS holesaws die quickly in stainless. The cobalt teeth on these saws hold up to 250-300 degrees C without losing their edge. Keep fluid on the cut, let the saw work at its own pace, and don't try to force it. The same techniques that ruin a Cobalt twist drill ruin a Cobalt holesaw.
Some users tap a self-tapping screw into the pilot hole, then grip and pull. Others use compressed air through the slots. Don't try to chisel the slug out by hand. The teeth are very sharp and the slug is hot.
Quick pick for Holesaws and Accessories:
If you are drilling: Holesaws cutting steel, stainless, timber, plastic
Pick: Bi-Metal Cobalt holesaw
Cobalt cutting teeth bonded to a tough spring-steel body. The cobalt edge takes the heat; the steel body absorbs the shock without cracking. Lasts many times longer than plain HSS in stainless.
Material & Coating
Bi-Metal Cobalt Construction: HSS Cobalt cutting teeth (approximately 5 percent cobalt) bonded to a tough spring steel body via electron-beam welding. The cobalt edge takes heat that standard HSS holesaws cannot.
Grade selection Holesaws cutting steel, stainless, timber and plastic at diameters from 14mm to 114mm+. The cobalt tooth edge lets the saw cut faster and last longer in stainless and hardened sheet.
Important Run at low RPM (roughly half what a twist drill at the same diameter would run), use cutting fluid on metal, withdraw frequently to clear chips and let the saw cool. Without fluid, the teeth blue and lose temper in a single cut.
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.
Not sure what 1/4" is in mm (or vice versa)? See our metric to imperial chart for the conversion every drill-bit size customers ask about.
About the Brand
Alpha · Sheffield Group · Australian
Alpha is the Sheffield Group's premium drilling, cutting and fastening brand. Australian-owned, Sheffield has supplied industrial and trade markets since 1957 and is one of the country's largest distributors of cutting tools and accessories.
Range: The Alpha range covers Gold Series HSS jobber drill bits, HSS Cobalt drill bits, Bi-Metal Cobalt holesaws, TurboBORE spade bits, heavy-duty timber augers, SDS Plus masonry bits, countersinks, ONSITE+ impact-rated step-tip drill bits, and the ThunderMax range of impact-driven accessories.
Positioning: Premium-quality, production-grade tools at trade pricing. Same-day dispatch from BNA Brisbane.
Pricing & Delivery
Includes GST, a Tax Invoice and Free Standard Delivery anywhere in Australia.
Buy with Confidence
15+ years selling online · 25,000+ stock lines · 200 million pieces ex-stock in Brisbane QLD.
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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. We only stock Alpha for this product; substituting another brand is rare and would always be confirmed with you first.
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 | HSV79 |
| UPC | 9342386014648 |
