GUN DRILL DESIGN

A gundrill consists of three components: tungsten carbide cutting tip, hardened steel shank and a soft steel driver.

Before drilling commences the gundrill must be suported by a guide bush or pre-drilled start hole. Coolant is delivered directly to the cutting edges through the hollow shank and the chips are evacuated back along the V configuration of the tip and shank.

The periphery of the cutting tip is contoured in such a way as to provide both support pads and lubrication galleries. The forces generated by the single sided cutting action act directly on the support pads creating a burnished surface finish and size control down to IT7 tolerances.

DRIVER DESIGN

STYLE REF d h h1
HAMMOND STANDARD
 CA 16 40  
CB 25 50  
CC 35 60  
       
AMERICAN STANDARD


 AA 1/2" 38 26
AB 3/4" 70 46
       
       
AC 1.00" 70 55
AD 1.25" 70 55
AE 1.50" 70 55
       
EUROPEAN STANDARD
 AF 10 40 24
AK 16 45 31
AG 20 70 34
AH 25 70 34
AJ 32 70 34

STYLE  REFdh h1
       
AN 16 50 47
       
WELDON
   BF 16 48 24
h2 BG 20 50 25
17 BH 25 56 32
19 BJ 32 60 36
19 BK 40 70 40
       
DG 10 60 M6X0.5
DH 16 80 M10X1.0
DK 25 100 M16X1.5
DL 36 120 M25X1.5
CH 16 112 Tr16-1.5
CJ 20 126 Tr20-2.0
CK 28 126 Tr28-2.0
CL 36 162 Tr36-2.0

These are the most commonly used driver styles. Hammond & Company hold many more in stock and will always produce to customer’s design.

When ordering please specify drill diameter, overall length, driver design and material to be cut. Click here if you prefer to order by product code.