Coventry Dieheads and Coventry Chasers

Genuine Coventry dieheads and Coventry chasers have become a by-word for external threading. Originally developed by Alfred Herbert and sold world-wide, the Coventry diehead is probably used in more countries than any other system.

In 2001, Namco Tooling acquired the complete Genuine Coventry chaser range, thus completing the most extensive portfolio of threading tools in Europe.

Original manufacturing drawings and records, dating back over 60 years, are now exclusive to Namco Tooling, along with all the necessary plant and equipment to meet world demand. Thousands of sets of standard Coventry chasers have been added to stock, and we are now offering an unrivalled service on specials.

Existing Coventry diehead users should note that we are offering the full range of lip grinds to suit most materials, including:

S-type, B-type, AM5, AM, S5, AS, M5.

S-20, B-33 and AM5 20 will continue to be our most widely available Coventry chasers, but all other combinations of lip and throat can be supplied rapidly from our huge stocks of blanks and semi-finished chasers.

Coventry Dieheads can be used on Turret lathes, CNC and automatic screw machines. The total system is noted for its ease and simplicity in setting, and for the accuracy of cut over a very wide range of thread variations. Automatic self-opening at the completion of each cut makes Coventry ideal for batch or continuous production work.

Product features

Rugged - simple construction for reliability and long life

Compactness - permitting use on machines with limited clearance

Accurate Pitch - due to the guiding action of the non-cutting portion of the die

Adjustability - providing fine regulation of finished diameter for 3a class threads

Clean and smooth threads - as the dies have cutting angles suited to the material being used

RH and LH thread - by only changing chasers

Parallel threads - due to the very efficient support of the dies in the diehead

Minimum downtime - for change of thread size, important for production economy on short to medium batch runs

Advantages of Coventry Chasers

Coventry chasers are designed so that cutting takes place at the chamfer and the first full tooth. The other teeth are above centre height, so they act as a nut, ensuring accurate pitch.

Chaser features:

• Precision ground threads
• Lip types to suit various materials
• Four standard chamfer angles: 15, 20, 33 and 45 degrees
  

The following lips are available across our entire range:

Coventry Die Sets - Stock items

Coventry Dies sorted by Diehead size

1/4" (6mm) | 5/16" (8mm) | 3/8" (10mm) |  1/2" (12mm)

3/4" (20mm) | 1" (25mm) |  1,1/4" | 1,1/2" | 2" | 2,1/2"