What does BSW 5/16" x 18 mean?

BSW stands for British Standard Whitworth thread according to BS 84 with a 55° flank angle. 5/16" is the outer diameter and 18 indicates 18 threads per inch (TPI).

What does Form D mean?

Form D is a medium chamfer, suitable for both through and blind holes, providing smooth chip formation and stable guidance.

For which materials is it suitable?

For non-abrasive, easily machinable materials up to about 900 N/mm², such as unalloyed and low alloyed steels.

Can it be used by hand and machine?

Yes, this tap is suitable for both hand and machine use. Ensure proper lubrication and alignment when cutting.

Where can I find tapping drill sizes?

You can find the matching core drill diameters in the Tapping Drill Size Chart (PDF) available here: https://voelkel.com/media/85/db/27/1658304905/13_Technical%20Information_Tapping%20drill%20sizes.pdf

What does BSW 5/16" x 18 mean?

BSW stands for British Standard Whitworth thread according to BS 84 with a 55° flank angle. 5/16" is the outer diameter and 18 indicates 18 threads per inch (TPI).

What does Form D mean?

Form D is a medium chamfer, suitable for both through and blind holes, providing smooth chip formation and stable guidance.

For which materials is it suitable?

For non-abrasive, easily machinable materials up to about 900 N/mm², such as unalloyed and low alloyed steels.

Can it be used by hand and machine?

Yes, this tap is suitable for both hand and machine use. Ensure proper lubrication and alignment when cutting.

Where can I find tapping drill sizes?

You can find the matching core drill diameters in the Tapping Drill Size Chart (PDF) available here: https://voelkel.com/media/85/db/27/1658304905/13_Technical%20Information_Tapping%20drill%20sizes.pdf

VÖLKEL single-cut machine tap M14 x 1.0, HSS-G, DIN 2181 Form D, for fine metric threads.

Technical drawing of a VÖLKEL thread tap with labeled diameters and lengths.

BSW - W (DIN 477)

Short Machine Tap DIN 352 Form D HSS-G - BSW 5/16 x 18

Name: VÖLKEL Short Machine Tap DIN 352 Form D HSS-G - BSW 5/16 x 18
Brand: VÖLKEL
SKU: 62316
Price: 5.00 EUR
Availability: InStock

Item no. 62316

€5.00

in stock - more than 100 pieces available

VÖLKEL delivers exclusively to specialized dealers. Online you can buy VÖLKEL products here.

The prices are in Euro plus VAT and shipping, insurance and packaging costs.

Application

VÖLKEL Short Machine Tap DIN 352 Form D HSS-G – BSW 5/16" x 18

The VÖLKEL Short Machine Tap made of HSS-G is designed for cutting precise Whitworth threads (BSW) according to BS 84 in size 5/16" x 18 TPI. Suitable for hand and machine use, it performs reliably in non-abrasive materials up to 900 N/mm² and can be used for through and blind holes.

Application & Advantages

For general-purpose use in workshops, maintenance, and production
HSS-G ground finish ensures clean cutting edges and long tool life
Suitable for unalloyed and low-alloy steels
For through and blind holes
Single-cut design for fast, accurate threading without pre- and finish taps

BSW, Form D & Tolerance Explained

BSW (British Standard Whitworth) is a 55° flank angle thread standard defined in BS 84. BSW 5/16" x 18 means 5/16 inch nominal diameter with 18 threads per inch.

Form D (DIN 352) refers to a medium chamfer used universally for both through and blind holes, offering a balanced cutting action and good chip flow.

Medium tolerance corresponds to the standard internal thread fit, providing smooth assembly with standard BSW screws.

Step-by-Step Instructions

Drill core hole: Use the correct drill size for BSW 5/16" x 18. Deburr and clean the hole.
Secure & align: Clamp the workpiece firmly and align the tap vertically.
Lubricate: Apply cutting oil or suitable lubricant.
Thread cutting: Rotate clockwise evenly, keeping the tap perpendicular.
Control depth: Stop at required depth (for blind holes) or complete (for through holes).
Clean & test: Remove chips, clean the thread, and check with a 5/16" BSW screw.

Technical Details

Thread type	Whitworth thread BSW (BS 84)
Standard	DIN 352
Form	Form D (medium chamfer)
Material	HSS-G
Nominal size	BSW 5/16" x 18 TPI
Overall length (L1)	56 mm
Thread length (L2)	22 mm
Shank diameter (D2)	6 mm
Square drive	4.9 mm
EAN	4022835623168
Article number	62316

FAQ

Is it suitable for stainless steel?
Primarily designed for non-abrasive, machinable materials. For stainless or hard steels, use HSS-E or HSCo taps.

Can it be used in a drill press?
Yes, when used with a proper collet or tap holder, correct speeds, and lubrication.

Where can I find the tapping drill size?
Refer to the Tapping Drill Size Chart (PDF) .

Are pre- or finish taps required?
No, this single-cut tap can be used directly for full threading.

How to detect wear?
Increased cutting force, rough thread surfaces, or burr formation indicate resharpening or replacement is needed.

Need help choosing the right tap or size? Contact us via the contact form.

Additional information

Type of thread	Whitworth-Thread
Standard	DIN 352
Form	Form D
Material	HSS-G
Tolerance	medium
Size	BSW 5/16 x 18
Overall length (L1)	56 mm
Thread length (L2)	22 mm
Core hole diameter (D1)	6.5 mm
Shank diameter (D2)	6.0 mm
Drive connector	4.9 mm
EAN	4022835623168
Item number	62316
Type of flute	straight fluted
Application	for through holes
Thread standard	BS 84