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Dormer Pramet A125 5.50 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Dormer Pramet A125 5.50 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

SKU:DOR-A1255.5X315

Meet a purpose-built deep-hole drilling ally: the Dormer Pramet A125 5.50 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328. This precision tool is engineered to tackle long reach p... Read more ↓
P
M
K
N
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TypeExtra Long Series
Drill Diameter5.50
Flute Length250
Overall Length310
Shank Diameter5.5
SubstrateHSS
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£32.83
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2 days estimated lead time — subject to availability
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Meet a purpose-built deep-hole drilling ally: the Dormer Pramet A125 5.50 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328. This precision tool is engineered to tackle long reach projects with confidence, delivering reliable performance from first cut to final depth.

Key features that matter on the shop floor

  • 118 degree conventional point for a strong, self-centering start that’s easy to re-sharpen, reducing downtime and preserving cutting edges between uses.
  • Steam oxide finish minimizes workpiece material adhesion to the cutting edge, helping chips flow freely and reducing built-up edge during demanding drilling sessions.
  • Extra-long length (310 mm) designed for drilling very deep holes or situations where reach matters—perfect for fabrication, automotive assemblies, and challenging workpiece geometries.
  • Premium HSS material capable of handling a wide range of materials, including steel, aluminum, and stainless steel, without compromising toughness or edge retention.
  • Straight shank provides broad compatibility with common drilling machines and tool holders, ensuring stable performance across various setups.

Designed for real-world use

Whether you’re drilling through metal plates, frames, or components with limited access, this drill delivers consistent hole quality and straightness. The A125 geometry is tuned for dependable starts and clean perforations, reducing the need for rework. Because it’s an HSS twist drill with a long, straight shank, it pairs seamlessly with drill presses, mill/turn centers, and handheld drilling rigs alike.

Ideal use cases

  • Deep-hole drilling in steel, stainless steel, and aluminum components where conventional-length tools fall short.
  • Fabrication and assembly work in automotive, aerospace, and general metalworking shops requiring extended reach.
  • Maintenance and repair tasks that demand a reliable, long-reach drill without changing tooling mid-project.
  • Situations where a durable, re-sharpenable point reduces downtime and extends tool life between dressings.

Practical tips for best results

  • Match cutting speed and feed with the material being drilled; start with a light, controlled engagement to seat the point and prevent wandering.
  • Use a light cutting fluid or coolant to manage heat buildup, especially when drilling stainless steel or other hard materials.
  • Peck drilling and occasional chip clearing are recommended for deeper holes to maintain cutting efficiency and prevent clogging.
  • Secure the workpiece firmly and ensure proper alignment to maximize hole accuracy over the 310 mm reach.

Type Extra Long Series
Drill Diameter 5.50
Flute Length 250
Overall Length 310
Shank Diameter 5.5
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

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You are viewing DOR-A1255.5X315. 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 Viewing5.502503105.5£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 8.502503108.5£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

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