Hexagon Socket Countersunk Head Screws

Hex-socket countersunk micro screws whose 90° head seats in a matching countersink for a flush finish.

Key specifications

Installationhex key or electric driver
StandardGB/T 70.3 (hex socket countersunk), GB/T 3098.1
Typical substratesheet-metal covers, instrument bases
Key inspectionshead angle, recess depth, thread gauging
Head TypeCountersunk (Flat)
Head stylecountersunk 90°

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Product overviewOverview

A countersunk screw centres itself on the 90° cone: as it tightens, the cone generates a radial component that aligns the screw, and the final clamp is carried by face contact between head and countersink. Compared with a cylindrical head, the load spreads over a larger cone area, which lowers contact pressure — but only if the countersink angle matches the head. A mismatch turns face contact into line contact and crushes the hole edge.

installed by hex key or electric driver.

Key featuresFeatures

90° cone seats in a matching countersink, leaving the surface flush.
Hex socket carries higher torque, suitable for structural joints from M2 to M6.
Cone centring reduces assembly eccentricity compared with a pan head.
6g thread tolerance for use with 6H internal threads; locking patches optional.

Typical applicationsApplications

Sheet-metal covers and faceplates
Robot joint housings
Instrument base plates and guide rails

Selection notesSelection

Countersink angle must equal the head angle (90° is standard); depth should follow the head diameter table, since an over-deep sink shortens the clamp length.

Frequently asked questionsFAQ

How do I specify the Hexagon Socket Countersunk Head Screws?

Countersink angle must equal the head angle (90° is standard); depth should follow the head diameter table, since an over-deep sink shortens the clamp length. installed by hex key or electric driver.

What matters during installation of the Hexagon Socket Countersunk Head Screws?

Turn it with a hex key or an electric screwdriver. 90° cone seats in a matching countersink, leaving the surface flush.

Specifications

Head Type	Countersunk (Flat)
Standard	GB/T 70.3 (hex socket countersunk), GB/T 3098.1
Head style	countersunk 90°
Installation	hex key or electric driver
Typical substrate	sheet-metal covers, instrument bases
Key inspections	head angle, recess depth, thread gauging

Manufacturing and inspection

Head angle is checked on a profile projector, and cone-to-shank concentricity against drawing tolerance.We recommend a pilot assembly at the actual torque and mating part before locking the process parameters for volume.