Hexagon Head Set Screws - Plain, Hi - Tensile (Grade 8.8), DIN 933, M30 X 70 mm

Overview

DIN 933 defines a hexagon head set screw with a fully threaded shank. The standard covers the dimensional form of the head, thread and length so the fastener can be selected consistently by diameter, thread and overall length. The fully threaded design is useful where thread engagement is required along the full length of the fastener, or where the screw is installed into a tapped hole rather than used with a nut.

This selected size is specified with diameter M30, length 70 mm, thread M30, pitch 3.5 mm.

Sold in multiples of '1 pieces. 1 Box = '1 pieces.

Material, Grade & Strength

Grade 8.8 is a high tensile carbon-alloy steel property class with a nominal ultimate tensile strength of approximately 800 MPa and a yield strength of approximately 640 MPa. It is widely used for engineering, structural and machinery joints requiring higher clamp load than ordinary mild steel fasteners. Torque must be selected from a recognised torque chart using the actual diameter, pitch, finish and lubrication condition. Use compatible high tensile nuts and washers so the mating part does not become the weak point.

Finish & Corrosion Protection

Plain finish fasteners have no protective plated coating and are best used indoors, in oiled assemblies, in painted structures or where corrosion exposure is controlled.

Typical Uses

DIN 933 set screws are commonly used in machinery, fabricated steelwork, brackets, frames, maintenance work and general engineering where a fully threaded hexagon head fastener is preferred.

Technical Tips

• Use DIN 933 where full thread engagement is required.
• For bolted joints, use a matching nut and washer of the same thread size and suitable strength class.
• For Grade 8.8, 10.9 or 12.9 parts, use correctly rated mating nuts and washers.
• Torque values vary by diameter, pitch, finish and lubrication; confirm the correct torque for critical assemblies.

Selection Advice

Choose DIN 933 when a fully threaded hexagon head fastener is required. Choose DIN 931 when the joint benefits from a partially threaded plain shank for alignment or shear loading.

Frequently Asked Questions

What is the difference between DIN 933 and DIN 931? DIN 933 is fully threaded, while DIN 931 is partially threaded. DIN 933 is often preferred for tapped holes or applications where the full length must provide thread engagement.