Please log in here to access all benefits, including promotional discounts and faster checkouts.

Dormer Pramet A125 8.50 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Dormer Pramet A125 8.50 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

SKU:DOR-A1258.5X315

Meet the Dormer Pramet A125 8.50 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328 — a purpose-built solution for precise, deep-hole drilling in metalworking tasks. Built for perfor... Read more ↓
P
M
K
N
S
TypeExtra Long Series
Drill Diameter8.50
Flute Length250
Overall Length310
Shank Diameter8.5
SubstrateHSS
View all specifications ↓
£47.88
Prices shown ex. VAT
2 days estimated lead time — subject to availability
View Other Sizes →
Free delivery over £50 ex VAT
Secure checkout
14-day returns
30+ years expertise
Klarna
Pay in 3 interest-free instalments. No extra cost if paid on time. 18+ only.
Learn more about Klarna
Speak to our team
01732 887334
Mon – Thurs 8:30 – 17:30 · Fri 8:30 – 16:30

Meet the Dormer Pramet A125 8.50 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328 — a purpose-built solution for precise, deep-hole drilling in metalworking tasks. Built for performance where reach matters, this drill combines a robust point geometry with a finish designed to keep the cut clean and consistent from start to finish.

  • 118-degree conventional point — delivers a strong, self-centering start that minimizes wandering and makes the edge easy to re-grind for continued accuracy over time.
  • Steam oxide finish — reduces friction and prevents workpiece material from sticking to the cutting edge, promoting smoother cuts and reduced heat buildup.
  • Extra-long length series — specifically engineered for drilling very deep holes and for applications where maximum reach is required, without sacrificing rigidity.
  • Premium HSS (High-Speed Steel) — versatile across materials such as steel, aluminium, and stainless steel, offering reliable performance in a range of metalworking projects.
  • Straight shank design — ensures compatibility with a wide array of drill presses, milling machines, and CNC setups, delivering consistent feed and chatter-free operation.
  • BS 328 compatibility — a proven standard that supports dependable interchangeability in professional shops and workshops.

Why choose this drill for deep-hole work? The A125’s combination of a durable HSS core and a geometry optimized for long reach means you can trust it to maintain cutting efficiency deeper into the hole, reducing the need for frequent tool changes. The 118-degree point helps you start cuts cleanly on metallic surfaces, while the steam oxide finish minimizes material adhesion, which is a common hurdle in continuous drilling sessions.

Ideal use cases

  • Deep-hole drilling in steel, aluminium, and stainless steel components, including tool housings, frames, and structural brackets.
  • Fabrication and maintenance tasks where access is limited and long stroke drilling is required.
  • Machining setups that rely on stable feeds in drill presses, milling machines, or CNC centers.

Practical tips for best results

  • Use a steady, controlled feed to prevent deflection in deep holes; peck drilling can help clear chips and prevent overheating.
  • Maintain appropriate lubrication to extend tool life and improve the finish on stainless and harder alloys.
  • Routinely regrind the point to preserve the 118-degree geometry for consistent starts and reduced chatter.

The Dormer Pramet A125 8.50 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328 is built for professionals who demand depth, reliability, and compatibility across a broad range of metalworking machines. When reach and precision matter, this drill delivers from first cut to last.

Type Extra Long Series
Drill Diameter 8.50
Flute Length 250
Overall Length 310
Shank Diameter 8.5
Substrate HSS
Coated Steam Tempered

What time are Protool open?

We are open Monday to Friday between 8:30am and 5pm.

Do you offer Free Next Day delivery?

Yes! We offer Free Next Day delivery via Royal Mail Tracked 24 on all orders over £50 ex VAT*. We also offer Free DPD Local Next Day delivery on all orders over £100 ex VAT*.

We also offer the following:

  • Royal Mail Tracked 24 — £5.90 (FREE on orders over £50 ex VAT*). Order before 4:30pm for next day delivery. No signature required.
  • DPD Local Next Day — £8.00 (FREE on orders over £100 ex VAT*). Standard next day delivery to UK mainland addresses.
  • Royal Mail Special Delivery — £12.50. Guaranteed delivery before 1pm the next working day.
  • DPD Saturday Delivery — £25.00. Must be ordered on Friday before 4pm. Pre-12pm delivery.

For delivery to Scottish Highlands & Islands, Northern Ireland, Republic of Ireland, or overseas locations, additional charges apply. Please see our delivery page for full details, or call us on 01732 887 334.

*T's & C's and exclusions apply. Please see our delivery page for more information on all our services.

★★★★★
Nice experience staff are very helpful and interested...
Staff are very helpful and interested in providing a good service making us the customer feel valued.
Bill
★★★★★
first place we look
honest about stock and prices are competitive.
Phil
★★★★★
Polite and helpful
Staff are very helpful and polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .
Graham
★★★★★
Buying experience
Phone requests are handled quickly and without any fuss. The website is easy to use and straightforward to order from. It’s especially helpful that it shows real‑time availability, so we don’t need to call to confirm whether parts will arrive.
Jeremy

Full Range: Dormer Pramet A125 HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILLS BS 328

View full collection →

You are viewing DOR-A1258.5X315. Click any other SKU to view its full details.

Product SKUDrill DiameterFlute LengthOverall LengthShank DiameterPriceStock Order
DOR-A1251.4X160 1.401001601.4£18.83 2 days
DOR-A1251.5X125 1.50801251.5£10.72 2 days
DOR-A1251.5X160 1.501001601.5£12.72 2 days
DOR-A1251/16X125 1/16801251.59£13.07 2 days
DOR-A1251/16X160 1/161001601.59£15.64 2 days
DOR-A1251.8X160 1.801001601.8£16.45 2 days
DOR-A1255/64X160 5/641001601.98£16.14 2 days
DOR-A1255/64X125 5/64801251.98£15.49 2 days
DOR-A1252.0X125 2.00801252£8.30 2 days
DOR-A1252.0X160 2.001001602£9.76 2 days
DOR-A1252.2X160 2.201001602.2£10.11 2 days
DOR-A1253/32X160 3/321001602.38£9.79 2 days
DOR-A1253/32X125 3/32801252.38£8.94 2 days
DOR-A1252.5X125 2.50801252.5£7.84 2 days
DOR-A1252.5X160 2.501001602.5£9.65 2 days
DOR-A1257/64X125 7/64801252.78£9.47 2 days
DOR-A1257/64X160 7/641001602.78£14.50 2 days
DOR-A1253.0X160 3.001001603£9.17 2 days
DOR-A1253.0X200 3.001502003£12.25 2 days
DOR-A1253.0X250 3.002002503£15.53 2 days
DOR-A1251/8X160 1/81001603.18£11.26 2 days
DOR-A1251/8X200 1/81502003.18£11.45 2 days
DOR-A1251/8X250 1/82002503.18£22.28 2 days
DOR-A1251/8X315 1/82503103.18£25.63 2 days
DOR-A1253.3X160 3.301001603.3£13.22 2 days
DOR-A1253.5X160 3.501001603.5£9.30 2 days
DOR-A1253.5X200 3.501502003.5£11.48 2 days
DOR-A1253.5X250 3.502002503.5£16.17 2 days
DOR-A1259/64X160 9/641001603.57£16.32 2 days
DOR-A1259/64X200 9/641502003.57£16.42 2 days
DOR-A1259/64X315 9/642503103.57£23.76 2 days
DOR-A1255/32X160 5/321001603.97£11.43 2 days
DOR-A1255/32X200 5/321502003.97£13.53 2 days
DOR-A1255/32X250 5/322002503.97£26.08 2 days
DOR-A1255/32X315 5/322503103.97£33.11 2 days
DOR-A1254.0X160 4.001001604£9.33 2 days
DOR-A1254.0X200 4.001502004£12.04 2 days
DOR-A1254.0X250 4.002002504£16.13 2 days
DOR-A1254.0X315 4.002503104£20.00 2 days
DOR-A12511/64X160 11/641001604.37£15.03 2 days
DOR-A12511/64X200 11/641502004.37£18.10 2 days
DOR-A12511/64X315 11/642503104.37£26.08 2 days
DOR-A1254.5X160 4.501001604.5£10.84 2 days
DOR-A1254.5X200 4.501502004.5£14.21 2 days
DOR-A1254.5X250 4.502002504.5£21.78 2 days
DOR-A1254.5X315 4.502503104.5£23.80 2 days
DOR-A1253/16X160 3/161001604.76£10.99 2 days
DOR-A1253/16X200 3/161502004.76£12.52 2 days
DOR-A1253/16X250 3/162002504.76£15.94 2 days
DOR-A1253/16X315 3/162503104.76£23.30 2 days
DOR-A1253/16X400 3/163004004.76£44.05 2 days
DOR-A1255.0X160 5.001001605£10.53 2 days
DOR-A1255.0X200 5.001502005£13.86 2 days
DOR-A1255.0X250 5.002002505£17.24 2 days
DOR-A1255.0X315 5.002503105£23.89 2 days
DOR-A1255.0X400 5.003004005£30.42 2 days
DOR-A12513/64X200 13/641502005.16£21.57 2 days
DOR-A12513/64X250 13/642002505.16£27.95 2 days
DOR-A12513/64X315 13/642503105.16£36.71 2 days
DOR-A1255.5X200 5.501502005.5£12.84 2 days
DOR-A1255.5X250 5.502002505.5£20.75 2 days
DOR-A1255.5X315 5.502503105.5£32.83 2 days
DOR-A1257/32X200 7/321502005.56£16.69 2 days
DOR-A1257/32X250 7/322002505.56£21.33 2 days
DOR-A12515/64X200 15/641502005.95£25.86 2 days
DOR-A12515/64X315 15/642503105.95£24.81 2 days
DOR-A1256.0X200 6.001502006£14.91 2 days
DOR-A1256.0X250 6.002002506£19.96 2 days
DOR-A1256.0X315 6.002503106£24.85 2 days
DOR-A1256.0X400 6.003004006£36.16 2 days
DOR-A1251/4X200 1/41502006.35£16.32 2 days
DOR-A1251/4X250 1/42002506.35£20.69 2 days
DOR-A1251/4X315 1/42503106.35£25.63 2 days
DOR-A1251/4X400 1/43004006.35£52.44 2 days
DOR-A1251/4X500 1/44004606.35£72.96 2 days
DOR-A1256.5X200 6.501502006.5£17.10 2 days
DOR-A1256.5X250 6.502002506.5£21.20 2 days
DOR-A1256.5X315 6.502503106.5£30.64 2 days
DOR-A12517/64X200 17/641502006.75£21.11 2 days
DOR-A12517/64X250 17/642002506.75£28.41 2 days
DOR-A12517/64X500 17/644004606.75£72.96 2 days
DOR-A1257.0X200 7.001502007£18.45 2 days
DOR-A1257.0X250 7.002002507£23.58 2 days
DOR-A1257.0X315 7.002503107£33.24 2 days
DOR-A1257.5X200 7.501502007.5£22.12 2 days
DOR-A1257.5X250 7.502002507.5£26.68 2 days
DOR-A1257.5X315 7.502503107.5£34.56 2 days
DOR-A1255/16X200 5/161502007.94£20.93 2 days
DOR-A1255/16X250 5/162002507.94£26.36 2 days
DOR-A1255/16X315 5/162503107.94£34.88 2 days
DOR-A1255/16X500 5/164004607.94£86.18 2 days
DOR-A1258.0X250 8.002002508£26.04 2 days
DOR-A1258.0X315 8.002503108£35.07 2 days
DOR-A1258.0X400 8.003004008£44.23 2 days
DOR-A12521/64X315 21/642503108.33£64.30 2 days
DOR-A1258.5X250 8.502002508.5£35.66 2 days
DOR-A1258.5X315 Viewing8.502503108.5£47.88 2 days
DOR-A12511/32X250 11/322002508.73£34.06 2 days
DOR-A12511/32X315 11/322503108.73£58.37 2 days
DOR-A12511/32X400 11/323004008.73£72.05 2 days
DOR-A12511/32X500 11/324004608.73£86.18 2 days
DOR-A1259.0X250 9.002002509£30.87 2 days
DOR-A1259.0X315 9.002503109£39.31 2 days
DOR-A1259.0X400 9.003004009£56.54 2 days
DOR-A1259.5X250 9.502002509.5£36.98 2 days
DOR-A1259.5X315 9.502503109.5£49.70 2 days
DOR-A1253/8X250 3/82002509.52£33.61 2 days
DOR-A1253/8X315 3/82503109.52£42.59 2 days
DOR-A1253/8X400 3/83004009.52£53.81 2 days
DOR-A1253/8X500 3/84004609.52£74.33 2 days
DOR-A12510.0X250 10.0020025010£35.52 2 days
DOR-A12510.0X315 10.0025031010£44.19 2 days
DOR-A12510.0X400 10.0030040010£65.21 2 days
DOR-A12513/32X250 13/3220025010.32£44.32 2 days
DOR-A12513/32X315 13/3225031010.32£54.72 2 days
DOR-A12510.5X250 10.5020025010.5£44.28 2 days
DOR-A12510.5X315 10.5025031010.5£57.46 2 days
DOR-A12510.5X400 10.5030040010.5£68.86 2 days
DOR-A12511.0X250 11.0020025011£40.04 2 days
DOR-A12511.0X315 11.0025031011£51.07 2 days
DOR-A12511.0X400 11.0030040011£63.38 2 days
DOR-A1257/16X250 7/1620025011.11£49.25 2 days
DOR-A1257/16X315 7/1625031011.11£62.02 2 days
DOR-A1257/16X400 7/1630040011.11£129.05 2 days
DOR-A12529/64X315 29/6425031011.51£57.46 2 days
DOR-A12512.0X250 12.0020025012£46.97 2 days
DOR-A12512.0X315 12.0025031012£54.72 2 days
DOR-A12512.0X400 12.0030040012£73.42 2 days
DOR-A12531/64X315 31/6425031012.3£57.46 2 days
DOR-A1251/2X250 1/220025012.7£57.00 2 days
DOR-A1251/2X315 1/225031012.7£72.96 2 days
DOR-A1251/2X400 1/230040012.7£95.76 2 days
DOR-A12513.0X315 13.0025031013£58.37 2 days
DOR-A12513.0X400 13.0030040013£74.33 2 days
DOR-A12517/32X315 17/3225031013.49£58.37 2 days
DOR-A12514.0X315 14.0025031014£69.31 2 days
DOR-A12514.0X400 14.0030040014£81.17 2 days
DOR-A1259/16X315 9/1625031014.29£69.31 2 days
DOR-A12537/64X315 37/6425031014.68£69.31 2 days
DOR-A12519/32X315 19/3225031015.08£69.31 2 days
DOR-A12519/32X500 19/3240046015.08£93.02 2 days
DOR-A1255/8X315 5/825031015.88£69.31 2 days
DOR-A1255/8X500 5/840046015.88£93.02 2 days
DOR-A12511/16X315 11/1625031017.46£69.31 2 days
DOR-A1253/4X315 3/425031019.05£70.68 2 days
DOR-A1253/4X500 3/440046019.05£95.30 2 days

View Other Sizes

with tools we think you'll like