Counterbore set DIN 373 HSS TiN middle

• M3 - M10 in metal box

Counterbores, also called flatsinks, are spiral fluted to process a flat sink of 180°, according to DIN 974-1. They are mainly used for sinking of Allen screws (hexagon socket screws) acc. To DIN 912, 6912, 7984, as well as for cylindric slotted screws acc. to ISO1207 (DIN 84), too.
Counter bores are used in through holes where the screws will connected with the nuts. Tapping sizes are used for tapping sized holes.

Available in three Versions

• for through holes (middle)
• for through holes (fine)
• for blind holes (tapping size)

HSS Countersink

steel, alloyed and unalloyed steel up to 900N/mm² tensile strength, grey cast iron,
malleable cast iron, spherodial and die cast, sintered iron, nickel-silver, graphit, short chipped
aluminium alloys, brass and bronze.

HSSE Countersink

hot and cold forming working tool- steels, acid and rust resistant steels (stainless steels: V2A/V4A)

Counter bores at processing

The sinking deepth will calculate as following:

Countersinking depth = Distances between tool point and the top surface of work piece + thickness of a possible use for a washer

Detailed Measurement

for sinking diameter 1.4 bis 6mm = 0.4mm

for sinking diameter 6 bis 20mm = 0,6mm

Application Progress

1. Drilling for counter sink

2. Measuring the head of bolt

3. Choosing the right dimension of counterbore

4. Generate the sinking

5. Countersink screwing