Structural Steel
Highly recommended and widely used for tapping structural steel.
Torque settings are based on these materials.
HMT VERSADRIVE CLUTCHED TAP ADAPTERS – TECHNICAL GUIDE
HMT Versadrive Clutched Tapping Adapters are designed for controlled blind-hole tapping, helping protect taps from breakage when the required tapping depth is reached. This guide covers material suitability, suitable machines, material thickness, lubrication, adapter selection, best practice, recommended impact torque and rotary RPM.
Which Materials Can Versadrive Clutched Tapping Adapters Be Used On?
Hardened Steel
This category of tooling is not generally suitable for hardened steel applications.
Stainless Steel
This category of tooling is not generally suitable for stainless steel applications where substantially more torque is required.
Non-Ferrous Metals
The taps are suitable for tapping aluminium and other non-ferrous metals.
Important: magnetic drills will not adhere directly to non-ferrous material.
Torque settings are factory set for structural steels, so application suitability must be considered carefully.
Which Machine Should I Use With Clutched Tapping Adapters?
| Machine | Suitable? | Guidance |
|---|---|---|
| Impact Wrench | Yes | 1/2" and 3/4" impact wrenches can be suitable for blind-hole tapping applications using the correct clutched adapter and torque setting. |
| Rotary Pistol Drill | No | Clutched Tapping Adapters are not suitable for this category of drilling machine. |
| Compact Magnet Drill | No | Clutched Tapping Adapters are not suitable for this category of drilling machine. |
| Large Magnet / Pillar Drill | Yes | Suitable for blind-hole clutched tapping where the machine has appropriate gear-speed options, variable speed and reversing. |
What Material Thickness Can Clutched Tapping Adapters Be Used On?
Sheet Metal
Up to 4 mm
Clutched Tapping Adapters are not suitable for this material thickness.
Standard Plate
5–12 mm
Clutched Tapping Adapters can be suitable for this application.
Typical tapping range: approximately M6–M8.
Medium Plate
12–25 mm
Clutched Tapping Adapters are suitable for this application.
Typical tapping range: approximately M6–M20.
Heavy Plate
Above 25 mm
Clutched Tapping Adapters are suitable for this application.
Which Cutting Lubricant Should I Use for Blind-Hole Tapping?
SpeedLube
Recommended for all blind-hole tapping applications.
BioCut Paste
Recommended for overhead drilling and other applications where liquid lubricant is not suitable.
BioCut Blue
Not recommended for blind-hole tapping.
Which Clutched Adapter Should I Use?
Impact Wrench Clutched Adapters
Use the HMT 131-series clutched adapters for impact-wrench applications.
These are designed for controlled blind-hole tapping with suitable Versadrive taps.
Morse Taper Clutched Adapters
Use the HMT 132-series clutched adapters for compatible Morse Taper machines.
These are suitable for controlled blind-hole tapping in appropriate reversible magnetic drills or pillar drills.
Pistol Drill / Chuck
Not applicable.
Weldon Adapters
Not applicable.
HMT Versadrive Clutched Tapping Best Practice
Do I need a pilot hole?
Yes.
Pilot drill the exact tapping-size hole to the required depth before tapping.
Correct pilot-hole size and depth are important for thread quality and reliable clutch operation.
What is the correct feed pressure?
Apply firm, steady starting pressure while tapping in forward, right-hand rotation.
The tap will then feed itself into the hole.
When the clutch engages, switch off the motor, select reverse or left-hand rotation, restart the machine and allow the tap to reverse out.
How long should the tap last?
There is no fixed number.
Tool life varies considerably depending on material, thread size, pilot-hole condition, machine, torque, lubrication and operating technique.
How can I prevent chipping or breakage?
Avoid lateral movement or tilting.
Do not use excessive feed pressure.
Keep the tool controlled and approximately square to the hole.
Maintain a consistent flow of swarf and use suitable lubrication.
What should I do when the clutch engages?
Once the blind hole has been tapped to the required depth, do not allow the clutch to continue engaging for more than a few seconds.
Prolonged clutch engagement can create heat and vibration and may contribute to tap breakage.
Stop the machine and reverse the tap out.
How can I avoid cross-threading?
When re-threading an existing thread, take care to locate the tap correctly in the existing thread.
Where possible, start the tap into the existing thread by hand before applying power.
How important is alignment?
Very important.
Ensure the tap is inserted squarely into the hole.
Poor alignment or an off-centre tap greatly increases the risk of tap breakage.
Recommended Impact Torque for HMT Versadrive Clutched Tapping
Recommended impact torque varies according to thread size and material thickness.
| Thread Size | Sheet up to 4 mm thick | Plate 5–12 mm thick | Plate 12–25 mm thick | Plate over 25 mm thick |
|---|---|---|---|---|
| M3–M4 | 95–110 | 105–120 | 160–180 | N/A |
| M5–M6 | 125–130 | 135–140 | 200–240 | N/A |
| M8–M10 | 140–160 | 150–170 | 280–300 | 430–480 |
| M12–M14 | 170–180 | 185–190 | 320–340 | 512–544 |
| M16–M20 | 190–295 | 200–315 | 360–400 | 576–640 |
| M24–M27 | N/A | N/A | 600–740 | 960–1184 |
| M30–M33 | N/A | N/A | 800–N/A | 1200–1400 |
| M36–M42 | N/A | N/A | N/A–N/A | 1640–2440 |
Recommended Rotary RPM for HMT Versadrive Clutched Tapping
For Morse Taper and other suitable rotary applications, recommended spindle speed varies according to thread size and material type.
| Thread Size | Structural Steel – 30 m/min | Hardened Steel – 8 m/min | Stainless Steel – 12 m/min | Non-Ferrous – 50 m/min |
|---|---|---|---|---|
| M3–M4 | 730–960 | 610–809 | 490–650 | 2060–2700 |
| M5–M6 | 485–585 | 405–485 | 325–385 | 1455–1750 |
| M8–M10 | 295–365 | 245–310 | 195–245 | 870–1095 |
| M12–M14 | 210–240 | 175–200 | 140–162 | 625–730 |
| M16–M20 | 145–185 | 125–155 | 100–125 | 440–550 |
| M24–M27 | 105–120 | 90–100 | 75–85 | 330–370 |
| M30–M33 | 84–95 | 68–80 | 51–60 | 265–310 |
| M36–M42 | 40–72 | 32–58 | 24–44 | 126–228 |