M4 Grade 12.9 Cr-Mo Alloy Steel Hex Socket Countersunk Flat Head Screws (1Pcs)

Product Description

SPEEDBULL premium high-strength screws are manufactured in Taiwan using Grade 12.9 chrome molybdenum (Cr-Mo) alloy steel and produced through a cold-forging process (not CNC-machined or turned), followed by precision heat treatment.

The forged construction preserves optimal grain flow within the material, resulting in superior structural integrity, higher tensile strength, and improved fatigue and impact resistance compared to CNC-machined screws. This makes them especially suitable for high-load and high-vibration applications.

Featuring a hex socket drive and a 90-degree countersunk flat head, these screws ensure precise seating, flush surface mounting, and secure fastening performance. Designed for demanding environments, they are ideal for RC racing, motorsport components, and precision mechanical assemblies where reliability and consistency are critical.

Key Features

Grade 12.9 Cr-Mo alloy steel

Cold-forged construction (not CNC machined)

Superior grain flow for enhanced strength and durability

90° countersunk flat head design

Hex socket drive for secure torque application

eat-treated for maximum mechanical performance

ade in Taiwan – SPEEDBULL quality selection

Specifications

Size: M4 × L

Material: Chrome Molybdenum Alloy Steel (Cr-Mo)

Strength Class: Grade 12.9

Manufacturing Process: Cold Forged

Drive Type: Hex Socket

Head Type: Countersunk Flat Head

Countersink Angle: 90°

Standard: DIN 7991 / ISO 10642

Surface Finish: Black Oxide