Screw M8x20

The Strofix screw M8×20 is an AISI 304 (A2) stainless-steel hex socket head cap screw manufactured to DIN 912 standard. The screw has an M8 thread and 20 mm length. It is tightened using a hex (Allen) key.

The DIN 912 hex socket cap screw is a standard fastener used in railing, balustrade, and architectural glass fixing assemblies. The recessed hex socket head allows flush or countersunk mounting where the bolt head must not protrude above the surface. The M8 thread matches the bolt pattern used in Strofix base plates with Ø8.5–9 mm bolt holes, such as the compact Ø80 mm round tube base plate and the 80 × 80 / 105 × 105 mm square tube base plates. The short 20 mm length is suited for shallow clamping applications where the bolt passes through thin components. AISI 304 (A2 grade) stainless steel provides corrosion resistance for both interior and exterior installations.

This SKU is a single fixed configuration — M8×20 mm, AISI 304 only.

Use cases:

• Glass clamp and glass adaptor bolt assemblies with M8 bolt pattern
• Securing components to base plates with Ø8.5–9 mm bolt holes
• Shallow clamping applications where a short 20 mm bolt is required
• General stainless-steel fastening in railing and balustrade systems
• Any M8 bolt application requiring a hex socket head in AISI 304

FAQ:

What are the screw dimensions?

The screw has an M8 thread and 20 mm length (M8×20 mm).

What standard does this screw conform to?

The screw is manufactured to DIN 912, which specifies hex socket head cap screws (also known as Allen bolts). This is equivalent to ISO 4762.

What tool is required?

A hex (Allen) key is required to tighten and loosen this screw. The hex socket is recessed into the bolt head.

How does this compare to the M10×45 screw?

This screw is M8 thread, 20 mm long — smaller and shorter. The M10×45 is M10 thread, 45 mm long. The M8×20 fits Ø8.5–9 mm bolt holes (compact base plates); the M10×45 fits Ø11 mm bolt holes (standard base plates). Choose based on the bolt hole size in the component being assembled.

What steel grade is used?

AISI 304, designated A2 under the European stainless-steel fastener classification.

About Anchors & Screws

Anchors and screws are the mechanical fasteners that secure glass adaptors, canopy brackets, railing posts, French balcony holders and other architectural hardware to the building substrate. They transfer structural loads from the visible hardware into concrete, masonry, insulated façades or timber frames.

Strofix supplies 16 products in this category: steel anchors in four lengths (150, 220, 320 and 400 mm) with rod diameters of Ø16 and Ø20 mm, an anchor sleeve (M10 × 80 mm), a spacer tube (L = 100 mm), individual screws (M10 × 45), cup nuts (M10), washers, double stainless-steel threads (M8, 60 and 100 mm), a wood screw (Ø10 × 180 mm), and pre-matched screw-and-fastener sets for 1, 2, 3 or 4 glass canopy brackets — configurable for masonry without insulation, masonry with insulation and timber-frame construction.

Materials are AISI 304 stainless steel and S235 structural steel. The correct fastener depends on wall type, hardware product, bolt size and required embedment depth.