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305mm x 7/16" Extension Bar for Heavy Duty Auger Bits Alpha WAH-EXT305
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| Buy 2 + | Buy 2 + | $38.00 each | $76.00 | 5.00% |
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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 | Imperial |
|---|---|
| Product | Auger Bit Extension Bar |
| Length (l) | 305mm |
| Body Diameter (n) | 19.00mm |
| Suitable For | 7/16" Hex Auger Bits |
| Body Length (b) | 57.00mm |
| Hex Size (h) | 7/16" |
| Packaging | Supplied in Plastic Tube |
| Brand | Alpha |
Dimensional data is a guide only. Tolerance differences exist between brands and batches
About Heavy Duty Auger Bits
Heavy Duty auger bits drill deep clean holes in timber under power. 7/16-inch hex shank for impact drivers and right-angle drills, 10mm-25mm+ diameters and 205mm-457mm working lengths. The screw-tip pilot pulls the bit through the timber without operator pressure; helical flutes clear chips cleanly even at depth. Standard kit for framing, mortising and electrical chases through stud walls and joists.
Recommended use General steel, alloy, brass, aluminium and timber drilling. Most cost-effective option for everyday workshop and site work. Holds an edge for hundreds of holes in mild steel when used with cutting fluid.
Frequently Asked Questions
Spade: flat-bottomed hole, cuts fast at the surface, can splinter the back face, needs operator pressure to feed. Auger: helical flute clears chips at depth, screw-tip pilot pulls the bit through under power, cleaner side walls, slower but better for deep holes. Auger wins for anything over 75mm deep or for serious framing work.
Spade bits and augers will splinter the timber as they exit because nothing supports the wood fibres at the back face. The pilot-through-then-flip technique gives a clean hole on both faces. A backing board works for repetitive work where flipping the piece is impractical.
Use a stud finder or metal detector before drilling into framing, especially older walls where electrical staples or nail plates may be hidden. If a bit hits steel mid-cut, pull out and switch to a metal-rated twist drill to finish through the obstacle.
On vertical or angled drilling, use a guide block clamped to the work, or a self-centring jig. For high-precision work like timber dowel joinery, a drill press gives the cleanest perpendicular hole.
Match the extension's hex size to the bit shank. For very deep holes (over 300mm), drill in stages: 100mm at a time, withdraw to clear chips, advance again. Forcing a deep cut in one pass overheats the bit and packs the flute.
For best results, work on a bench with the bit clamped, follow the original cutting angle, and equalise both sides. A bench grinder works for heavy reshaping but removes a lot of material quickly. Learn on cheap bits first.
Quick pick for Auger Bits Heavy Duty:
If you are drilling: Deep timber holes, framing, mortising, electrical chases
Pick: Heavy duty tool-steel auger bit
Through-hardened tool steel with a sharp screw-tip pilot that self-feeds under power. Helical flutes clear chips at depth. The right pick for any timber hole over 75mm deep.
Material & Coating
HSS M2 high-speed steel (HSS). The everyday cutting-tool steel for drill bits. Hardness approximately 800 to 900 HV with an operating temperature range up to ~600 degrees C before the cutting edge anneals.
Important Use cutting fluid (light machine oil, kerosene or proper cutting compound) on steel and stainless to keep the cutting edge cool. Without fluid, temperature rises into the annealing range and the edge dulls quickly. Aluminium can be drilled dry; cast iron drills dry.
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.
Excellent on REVIEWS.ioTrusted by DIYers, tradespeople, builders, manufacturers, government, councils and engineers across Australia · Read reviewsDisclaimer
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 | WAH-EXT305 |
| UPC | 9342386048391 |
