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Description
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Sicurezza del prodotto
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Description
Cobalt HSSE Tapping Insert M4 — for threading steel, stainless steel, aluminum, and non-ferrous metals. Manufactured in Austria by Bernardo; Krollit has been an official distributor in Italy since 2007.
- Tap diameter: M4 (Ø 4 mm)
- Metric thread pitch: 0.7 mm
- Material: HSSE (high-speed steel with cobalt)
- Compatibility: Bernardo TM and STG series tapping machines
- Standard: DIN 371 / DIN 376
Workable materials and limits
| Material | Suitable | Notes |
|---|---|---|
| Mild steel S235/S275 | Yes | Standard speed, no problems |
| Stainless steel AISI 304/316 | Yes | Reduce speed by 50%, abundant coolant/lubricant |
| Aluminum and alloys | Yes | Maximum speed, specific oil for aluminum |
| Cast iron | Yes | Dry cutting or with compressed air |
| Steels over 1,000 N/mm² | No | Require specific carbide inserts |
Technical specifications
| Specification | Value |
|---|---|
| Thread size | M4 |
| Metric thread pitch | 0.7 mm |
| Insert material | HSSE (high-speed cobalt steel) |
| Standard | DIN 371 / DIN 376 |
| Max. material strength | 800 N/mm² |
Logistics
Original spare parts available with 3–5 business day shipping. Customer service available in Italian.
Frequently asked questions
What is an HSSE insert and how does it differ from standard HSS?
HSSE (High Speed Steel with Cobalt) is high-speed steel with added cobalt (5–8%). Cobalt increases hot hardness and wear resistance: HSSE inserts better withstand the temperatures generated by tapping tough materials such as AISI 304 stainless steel, chromium-molybdenum steels, and hard cast irons. On mild steel and aluminum, the difference compared to standard HSS is minimal; on stainless steel and hard materials, the lifespan can be 3–5 times longer.
Is this insert compatible with my Bernardo tapping machine?
Bernardo HSSE inserts are compatible with TM and STG series tapping machines. Check your machine's spindle connection (GT 12 or GT 24) before purchasing. For compatibility confirmation, contact Krollit. Customer service available in Italian.
What is the correct speed for tapping with an HSSE insert?
On mild steel S235: 10–15 m/min. On AISI 304 stainless steel: 3–6 m/min with abundant coolant/lubricant. On aluminum: 15–25 m/min. Peripheral speed is calculated: n (rpm) = (v × 1000) / (π × d). Always use coolant/lubricant — HSSE inserts resist heat but wear faster without lubrication.
Delivery times?
Original spare parts available with 3–5 business day shipping. Customer service available in Italian.

