- 98% satisfied customers
- 72h delivery
- 30 dni na zwrot
Description
DIAMETER Ø25.5 mm
MORSE TAPER MT3
OVERALL LENGTH 286 mm
FLUTE LENGTH 165 mm
Technical specifications of the Ø25.5 mm drill bit
Twist drill with Morse taper shank
| TECHNICAL DATA | |
|---|---|
| Diameter | Ø25.5 NWKc HSSE |
| Standard | DIN 345 |
| Drill type | NWKc — twist drill with taper shank |
| Material | HSSE (cobalt high-speed steel) |
| Overall length l1 | 286 mm |
| Flute length l2 | 165 mm |
| Morse taper | MT3 |
| Point angle | 118° |
| Diameter tolerance | h8 |
| Cutting direction | Right-hand |
Ø25.5 mm HSSE twist drill – MT3 Morse taper
Product description and key benefits
The Ø25.5 mm metal drill bit with an MT3 Morse taper is a tool in the diameter range where the MT2 taper no longer provides sufficient contact area. DIN 345 specifies an MT3 taper with a diameter of 23.83 mm for drill diameters of 23–31 mm, transmitting the torque generated when drilling heavy steel structures. The Ø25.5 Morse taper drill bit requires a pillar or box-column drilling machine with a power rating of at least 1.5 kW.
Key benefits of the Ø25.5 mm metal drill bit
- HSSE steel with 5% cobalt — heat resistance up to 650°C allows drilling in 304/316 stainless steels without rapid dulling of the cutting edge
- Morse taper MT3 — self-holding mounting in the spindle eliminates slippage at the high cutting torques generated in difficult-to-machine steels
- Increased hot hardness — cobalt in the steel matrix increases resistance to tempering — essential at low Vc and the high cutting resistance of austenitic steels
- DIN 345 — full interchangeability with HSS drills of the same size and compatibility with reduction sleeves
- Flute length 165 mm — drilling through holes in components up to 150 mm thick
- Machining INOX steel without coatings — HSSE geometry and composition allow drilling in acid-resistant steels without TiN/TiAlN coatings
The Ø25.5 mm Morse taper drill is selected for holes for pins, bearing bushings, and flanged connections in machinery manufacturing. It is suitable for machining foundation plates and bearing end shields. H12 tolerance holes (Ø25.500–Ø25.710 mm); tighter fits are achieved by reaming or boring.
Morse tapers – dimensions to DIN 228
Dimension table for all Morse tapers MT0–MT6
| Taper | Diameter D [mm] | Length [mm] |
|---|---|---|
| MT0 | 9.045 | 49.8 |
| MT1 | 12.065 | 53.5 |
| MT2 | 17.780 | 64.0 |
| MT3 | 23.825 | 80.5 |
| MT4 | 31.267 | 117.5 |
| MT5 | 44.399 | 149.5 |
| MT6 | 63.348 | 210.0 |
REDUCTION SLEEVES COMPATIBLE WITH THE Ø25.5 MM DRILL BIT:
| ✓ | MT3 → MT4 — for a spindle with an MT4 socket |
| ✓ | MT3 → MT5 — for a spindle with an MT5 socket |
| ✓ | MT3 drill drift — for removing the drill bit from the spindle |
Cutting data for the Ø25.5 mm drill bit according to ISO 513
Recommended machining conditions for a diameter of Ø25.5 mm
| ISO symbol | Workpiece material | Vc [m/min] | f [mm/rev] | n [rpm] | Vf [mm/min] |
|---|---|---|---|---|---|
| P Steel | Structural steel up to 900 N/mm² | 11÷20 | 0.20 | 137÷250 | 27÷50 |
| K Cast iron | Gray cast iron GG20–GG30 | 13÷16 | 0.20 | 162÷200 | 32÷40 |
| N Copper and Al alloys | Cu, CuZn, Al, and alloys | 25÷28 | 0.25÷0.32 | 312÷350 | 78÷112 |
Deep-hole drilling (over 3×D)
When drilling holes deeper than 76 mm (3×Ø25.5), use peck drilling with retraction every 1×D. Use ample emulsion coolant at a minimum concentration of 6–8%. Reduce the feed by 30–50%.
Material compatibility of the Ø25.5 mm drill bit
Range of workpiece materials and application limitations
✓ Structural steel (S235, S355) up to 900 N/mm²
✓ Gray and ductile cast iron (GG20, GGG40)
✓ Low-carbon and medium-alloy steel
▲ Stainless steel (Vc reduced by 30%, ample coolant)
▲ Aluminum and Al alloys (emulsion coolant required)
✗ Hardened steels above 45 HRC
Frequently asked questions about the Ø25.5 mm drill bit
Spot drilling is not necessary on flat surfaces in structural steels. Spotting with a 90° NC spotting drill is recommended when drilling on inclined surfaces, castings with machining allowance, and flame-cut surfaces.
The HSS drill can handle stainless steel with Vc reduced by 40% and ample coolant. For regular INOX machining, an HSSE (cobalt) drill of the same diameter is recommended.
A pillar or box-column drill press with an MT3 spindle and a power rating of at least 1.5 kW. For diameters above 25 mm, power feed is recommended — manual feed will not provide uniform pressure.
Product accessories
Reduction sleeve MK4 MK3 1751 PTPa DIN 228
Reference: 1180 In stock > 10 items
€18.42
€22.66 brutto
Reduction sleeve MK6 MK3 1751 PTPa DIN 228
Reference: 11965 In stock < 10 items
€36.84
€45.32 brutto
Reduction sleeve MK5 MK3 1751 PTPa DIN 228
Reference: 5702 In stock > 10 items
€26.32
€32.37 brutto
Reviews
No customer reviews for the moment.
Shipping
All orders are delivered by courier company GLS. For orders exceeding 369 PLN gross shipping is FREE
| Courier GLS | Przelew24 / Prepayment | 14,76 zł gross | Delivery time 1 working day |
| Courier GLS | Cash on delivery | 17,26 zł gross | Lead time 1 working day |
Recommended for you
This website uses its own and third-party cookies to improve our services and show you advertising related to your preferences by analyzing your browsing habits. To give your consent to its use, press the Accept button.
Cookie preferences
Functional cookiesTechnical
Functional cookies are strictly necessary to provide the services of the shop, as well as for its proper functioning, so it is not possible to refuse their use. They allow the user to browse through our website and use the different options or services that exist on it.
Advertising Cookies
These are cookies that collect information about the advertisements shown to users of the website. They can be anonymous, if they only collect information about the advertising spaces shown without identifying the user, or personalised, if they collect personal information about the user of the shop by a third party, for the personalisation of these advertising spaces.
Analytics cookies
Collect information about the user's browsing experience in the shop, usually anonymously, although sometimes they also allow the user to be uniquely and unequivocally identified in order to obtain reports on the user's interests in the products or services offered by the shop.