Specify a forming-hole diameter before treating chipless threading as a cutting-tap replacement.
The HSS-Co metric thread forming tap shapes an internal thread by displacing suitable ductile workpiece material instead of cutting chips. Nine listed sizes cover M2 × 0.4 to M12 × 1.75. Its dedicated pilot-hole values are a central selection detail, not an accessory note.
Dimensions are in millimetres except thread designations, drive labels and lead counts. Read each column with the dimension reference below.
| Thread / designation | Overall length L (mm) | Working / cutting length Lc (mm) | Listed diameter d (mm) | Square / drive k (mm) | Pilot reference (mm) |
|---|---|---|---|---|---|
| M2x0.4 | 40 | 12 | 3 | 2.5 | 1.8 |
| M2.5x0.45 | 44 | 14 | 3 | 2.5 | 2.3 |
| M3x0.5 | 46 | 11 | 4 | 3.2 | 2.8 |
| M4x0.7 | 52 | 13 | 5 | 4 | 3.7 |
| M5x0.8 | 60 | 16 | 5.5 | 4.5 | 4.6 |
| M6x1.0 | 62 | 19 | 6 | 4.5 | 5.5 |
| M8x1.25 | 70 | 22 | 6.2 | 5 | 7.4 |
| M10x1.5 | 75 | 24 | 7 | 5.5 | 9.3 |
| M12x1.75 | 82 | 29 | 8.5 | 6.5 | 11.2 |
Use the forming-hole references with the actual ductile material and agreed hole tolerance; they are not cutting-tap drill values.
The M6 × 1.0 entry specifies a 5.5 mm pilot reference, 62 mm overall length, 19 mm working-section length, 6 mm shank and 4.5 mm square. Final hole tolerance must be agreed for the actual material and required thread acceptance.
Consider forming where the workpiece has sufficient ductility and the tapping setup can provide the required lubrication and torque. Share the alloy and hardness where known, together with the thread depth and hole type.
Do not use a cutting-tap drill chart for this tool. Brittle materials and poorly controlled holes require a different assessment. Chipless operation does not remove the need for lead clearance at the bottom of a blind hole.
| Product family | Selection boundary to review |
|---|---|
| HSS Metric Spiral Flute Machine Tap | General metric return-chip spiral flute series for blind-hole selection; retain the published dimensions. |
| HSS Metric Straight Flute Machine Tap | Build a metric assortment around the actual shank and square dimensions—not thread size alone. |
| M35 Spiral Flute Tap for Aluminium | Source the aluminium-focused M35 series without confusing tool grade with thread size. |
Keep the selected family, thread designation and dimensional reference together. Shared nominal sizes or drive shapes do not establish interchangeability.
For forming taps, control starts with the distinction between displacement and cutting. Carry the ductile-material brief and the forming-hole requirement into sample and order discussions; a similarly sized cutting tool does not answer that brief.
Use forming tap in the requested tool or pack identification and include the approved size/pitch. Keep the agreed pre-hole specification with technical documents rather than replacing it with a generic cutting-tap drill chart.
Carry the HSS-Co requirement with the item drawing when discussing material preparation for this range.
Keep the approved item identity and dimensional revision with components during order discussions. Use the exact thread and drive dimensions to distinguish similar tools.
The pre-hole specification is an acceptance priority because small diameter changes affect the forming operation. Agree the tool dimensions, material requirement and finished-thread acceptance separately.
Use the following items to define the sample and order acceptance brief.
| Review item | What to agree | Procurement risk addressed |
|---|---|---|
| Thread identification | Nominal size, required pitch and finished-thread requirement | Avoid the wrong thread family or pitch |
| Dimensions and holding | The M6 × 1.0 entry specifies a 5.5 mm pilot reference, 62 mm overall length, 19 mm working-section length, 6 mm shank and 4.5 mm square. Final hole tolerance must be agreed for the actual material and required thread acceptance. | Avoid holder mismatch, insufficient reach or unintended substitution |
| Geometry / set identity | The pre-hole specification is an acceptance priority because small diameter changes affect the forming operation. Agree the tool dimensions, material requirement and finished-thread acceptance separately. | Avoid the wrong cutting form or incomplete member sequence |
| Sample acceptance plan | Agree the reference drawing, acceptance method and sampling requirement for the application | Make sample approval and repeat-order review refer to the same item |
Keep the forming operation explicit in your RFQ and item description. Supply the incoming hole diameter and tolerance alongside the thread requirement so a forming tap cannot be substituted with a similarly sized cutting tap during replenishment.
Use forming tap in the requested tool or pack identification and include the approved size/pitch. Keep the agreed pre-hole specification with technical documents rather than replacing it with a generic cutting-tap drill chart.
Specify a forming-hole diameter before treating chipless threading as a cutting-tap replacement.
A forming tap displaces ductile material to make the thread; a cutting tap removes material as chips. They need different pilot-hole specifications and application checks.
The source size table lists 5.5 mm. Treat that as a forming-hole starting reference and agree the final tolerance for the workpiece and thread acceptance requirement.
Do not use that cutting-tap shortcut for this forming range. For example, the listed M6 forming reference is 5.5 mm rather than the 5 mm cutting-tap reference.
No. Material ductility, hole control, lubrication and torque all matter. Send the specific alloy and condition; a broad description such as metal is insufficient for selection.
The lead still needs clearance. State drilled depth and required full-thread depth separately so the remaining space can be assessed.
Include thread and tolerance, workpiece alloy, pre-hole diameter and tolerance, thread depth, holder, lubricant and sample acceptance criteria. Identify HSS-Co as the requested tool material.
Send the selected thread designation, quantities and the application details below. Add a drawing or size list to keep the enquiry tied to the required configuration.