DIN 6537 Standard Sizes · Coolant-Thru Drill Depth Ratio
25D DIN 6537 Carbide Coolant-Thru Drills
These are German DIN 6537 standard-size coolant-through carbide drills. The deepest ratio in the standard range. The 25D coolant-thru drill is specified for aerospace structural drilling, long-reach cooling holes in injection moulds, and medical implant manufacturing. Requires a high-pressure coolant system (≥60 bar) and a machining centre with minimal thermal growth. Custom geometries available on request.
Applications
Aerospace structural holes · Long mould cooling channels · Medical implant features · Maximum-depth precision drilling
Feed-In Method
Use a precision pilot, rigid fixturing, and conservative feed-in. Confirm the process on sample parts before scaling production.
Pilot Hole
Required. Use a matched pilot drill and verify pilot depth, diameter, and alignment before the 25D tool enters.
Coolant Requirement
Internal coolant at 60-80 bar is normally required. Flow stability and filtration are critical at this depth.
25D DIN 6537 SKU Range
Complete 25D DIN 6537 Coolant-Thru Drill Sizes
Maximum depth — aerospace, mould cooling, medical implants
| CUTTER DIA (D1) h7 | FLUTE LENGTH (L2) | SHANK DIA (D2) h6 | OVERALL LENGTH (L1) | Price | SKU PAGE | |
|---|---|---|---|---|---|---|
| 3.00 | 0.1181 | 85.00 | 4.00 | 117.00 | $26.28 | Details |
| 3.50 | 0.1378 | 116.00 | 4.00 | 148.00 | $34.89 | Details |
| 4.00 | 0.1575 | 116.00 | 4.00 | 148.00 | $34.89 | Details |
| 4.50 | 0.1772 | 145.00 | 6.00 | 183.00 | $58.42 | Details |
| 5.00 | 0.1969 | 145.00 | 6.00 | 183.00 | $58.42 | Details |
| 5.50 | 0.2165 | 170.00 | 6.00 | 210.00 | $67.74 | Details |
| 6.00 | 0.2362 | 170.00 | 6.00 | 210.00 | $67.74 | Details |
| 6.50 | 0.2559 | 197.00 | 7.00 | 237.00 | $89.53 | Details |
| 7.00 | 0.2756 | 197.00 | 8.00 | 237.00 | $103.21 | Details |
| 7.50 | 0.2953 | 220.00 | 8.00 | 260.00 | $113.98 | Details |
| 8.00 | 0.3150 | 220.00 | 8.00 | 260.00 | $113.98 | Details |
| 8.50 | 0.3346 | 250.00 | 10.00 | 294.00 | $168.99 | Details |
| 9.00 | 0.3543 | 250.00 | 10.00 | 294.00 | $168.99 | Details |
| 9.50 | 0.3740 | 277.00 | 10.00 | 321.00 | $185.29 | Details |
| 10.00 | 0.3937 | 277.00 | 10.00 | 321.00 | $185.29 | Details |
Process Notes
What to Confirm Before Running 25D
Feed-In
Use a precision pilot, rigid fixturing, and conservative feed-in. Confirm the process on sample parts before scaling production.
Pilot Hole
Required. Use a matched pilot drill and verify pilot depth, diameter, and alignment before the 25D tool enters.
Cooling
Internal coolant at 60-80 bar is normally required. Flow stability and filtration are critical at this depth.
RFQ Data
Send full drawing, hole depth, entry/exit condition, machine/coolant data, material, tolerance, coating, and annual quantity.
RFQ Checklist
Quote 25D DIN 6537 coolant-thru drills faster
- Diameter list and quantities
- Work material and hardness
- Hole depth, blind/through condition, tolerance
- Coolant pressure, filtration, machine/toolholder
- Coating preference and annual quantity