Halco Rock Tools, UK Manufacturer of DTH Hammers and Bits. Halco pioneered the development and distribution of DTH hammers in the 1950s.
The GP500 high performance hammer drills under a head of water typically suited to Waterwell and Geothermal applications due to its non-ported piston design.
 
It features a choke facility which helps to adjust air flow through the hammer.
Choke system to allow adjustment of air flow to improve flushing.
3/16" Plug
1/8" Plug
Optimised drive chamber capacities to maximise hammer performance.
Blank
Plug
Robust simple piston design for optimum strength and performance.
Air Consumption
A captive bit retaining ring makes changing the drill bit easier.
Size
140-165mm
(5 1/2-6 1/2")
Shank
DHD350
Air Pressure
100-435PSI
(7-30 bar)
Tech Specs
Overview
GP500
Hammer Type
Part Number
Shank
Top Thread
Hammer Flat Size
Weight
Outside Diameter
Make Up Length
Recommended Maximum Thrust
600426
DHD350R
3 1/2" API Reg Pin
66mm (2.560") 
60Kg
126mm (4.961")
1074mm (42.283")
900Kg (1980 lbs)
600429
DHD350R
2 3/8" API Reg Pin
64.75mm (2.549") 
60Kg
126mm (4.961")
1074mm (42.283")
900Kg (1980 lbs)
Drill Bit Overview
DHD350R
Oversize
 
 
 
 
Y
Y
Y
Weight
(Kg)
16.4
16.2
15.9
16.16
16.45
17.8
17.8
21.4
 
Part
Number
650677
653205
653070
653272
650772
650676
653711
653092
 
Diameter
Face
Buttons
mm
140
140
140
140
140
150
152
165
 
Inch
5 1/2
5 1/2
5 1/2
5 1/2
5 1/2
5 7/8
6
6 1/2
 
Qty & Dia
8 x 16mm / 7 x 16mm
7 x 16mm / 8 x 16mm Long
8 x 16mm / 8 x 16mm Long
8 x 16mm / 8 x 16mm
15 x 16mm
9 x 16mm / 10 x 16mm
20 x 16mm
10 x 16mm / 8 x 20mm
Design
Concave
Flat
Convex
Flat
Concave
Concave
Convex
Concave
 
Type
Dome /S-Ballistic
Dome
Semi-Ballistic
Dome / S-Ballistic
Dome
Dome /S-Ballistic
Convex
Concave
 
Additional bit configurations are available on request.