You use Hand Tap Bottoming JIS B-4430 Form C HSS-G - BSW 5/16 x 18 to cut internal threads in metal parts. The tool is chosen when alignment and torque control are important for thread quality.
The designation BSW 5/16 x 18 identifies the thread you cut. BSW means British Standard Whitworth, an inch based thread system common on legacy and repair work. HSS-G indicates ground high speed steel, typically chosen for accurate geometry and consistent cutting action. The reference JIS B-4430 provides a common specification framework for the tool form and designation.
Note Use suitable cutting fluid and stop if torque rises unexpectedly, then inspect alignment and chip evacuation.
How do you select the correct thread designation for this tool
Match the designation BSW 5/16 x 18 to the drawing and mating part, then confirm that the hole type and process match the tool design.
Which holder is typically used for manual tapping
A tap wrench that clamps the square shank is the typical choice, and you keep the tool axis aligned to the hole to reduce side load.
What does the stage name in the product name tell you
Stage names such as rougher, intermediate, finisher, taper, or bottoming indicate the intended chamfer and entry behavior, so you can plan the tapping sequence and hole depth.
Which workpiece materials are typical for this threading tool
Thread cutting tools are commonly used in steels, cast iron, and many non ferrous alloys, but you should adapt lubricant choice and process control for hard, sticky, or abrasive materials.
What does BSW mean in the thread designation
BSW means British Standard Whitworth, an inch based thread system common on legacy and repair work.
Do you need lubrication and how do you manage chips
Use a cutting fluid suitable for the material to reduce friction, and clear chips from the flutes during the process to keep torque stable.
Where can you find additional technical information for selection and standards
For an overview of threading tools and related standards, refer to the VD 23 catalog as PDF.
Do you need help selecting or using the product?
Use the contact form.
| Type of thread | Whitworth-Thread |
|---|---|
| Standard | JIS B-4430 |
| Form | Form C |
| Material | HSS-G |
| Tolerance | medium |
| Size | BSW 5/16 x 18 |
| Overall length (L1) | 70 mm |
| Thread length (L2) | 30 mm |
| Core hole diameter (D1) | 6.5 mm |
| Shank diameter (D2) | 6.1 mm |
| Drive connector | 5.0 mm |
| Item number | 94416-3 |
| Type of flute | straight fluted |
| Application | for blind holes |
| Thread standard | BS 84 |









