Home » GB/T 9074.13-1988 Cross Recessed Hexagon Bolt with Indentation, Single Coil Lock Washer and Plain Washer Assemblies - Stainless Steel A2

GB/T 9074.13-1988 Cross Recessed Hexagon Bolt with Indentation, Single Coil Lock Washer and Plain Washer Assemblies - Stainless Steel A2

GB/T 9074.13-1988 Cross Recessed Hexagon Bolt with Indentation, Single Coil Lock Washer and Plain Washer Assemblies — Stainless Steel A2

FULLERKREG supplies GB/T 9074.13-1988 stainless steel A2 SEMS screws — pre-assembled three-piece fastener assemblies combining a cross recessed hexagon bolt, a single coil spring lock washer, and a plain washer into one captive unit. Designed for high-efficiency assembly in electrical enclosures, sheet metal fabrication, and precision mechanical structures.

What Are GB9074.13 Cross Recessed Hex SEMS Screws?

GB/T 9074.13-1988 defines a three-piece pre-assembled fastener (SEMS) consisting of:

  • GB29.2 — Cross recessed hexagon head bolt (Phillips drive, hex head)
  • GB9074.24 — Plain washer (assembly-grade flat washer)
  • GB9074.26 — Single coil spring lock washer (assembly-grade spring washer)

The three components are permanently captivated onto the bolt shank before threading. After the thread is rolled, the outer thread diameter exceeds the inner diameter of the plain washer, making the assembly inseparable. This eliminates loose washers on the assembly line and dramatically reduces installation time.

Assembly formula: GB9074.13 = GB29.2 + GB9074.24 + GB9074.26

The washer stack order from bolt head outward is: Plain Washer → Spring Lock Washer → Bolt Head (the plain washer sits closest to the workpiece surface).

Benefits of Using GB9074.13 Cross Recessed Hex SEMS Screws

  • ✅ No loose parts — washers are permanently captivated; no risk of dropped or missing washers during assembly
  • ✅ Faster installation — one-piece handling replaces three separate components; ideal for automated and manual assembly lines
  • ✅ Correct washer sequence guaranteed — plain washer always contacts the workpiece; spring washer always contacts the bolt head flange
  • ✅ Vibration resistance — the coil spring lock washer provides reliable anti-loosening performance under dynamic loads
  • ✅ Dual drive flexibility — cross recessed (Phillips) drive on a hex head allows both manual screwdriver and power tool / wrench tightening
  • ✅ Corrosion resistance — A2 (SUS304) stainless steel with passivation finish for long service life in humid and mildly corrosive environments
  • ✅ Reduced inventory complexity — one SKU replaces three separate fastener SKUs

Material & Finish

Property Specification
Material A2 Stainless Steel (SUS304 / 18-8)
Surface Finish Natural (Bright Passivated)
Property Class A2-70
Tensile Strength ≥ 700 MPa
Yield Strength (0.2% proof) ≥ 450 MPa
Corrosion Resistance Excellent — suitable for indoor, outdoor, and mildly corrosive environments
Magnetic Slightly magnetic (work-hardened 304)
RoHS Compliant Yes

Dimensions of Pre-Assembled Washers in GB9074.13 Hex Head SEMS Screws

Washer dimensions conform to GB9074.24 (plain washer) and GB9074.26 (spring lock washer). All dimensions in millimeters (mm).

Plain Washer Dimensions (GB9074.24)

Thread Size Inner Dia. d₁ (mm) Outer Dia. d₂ (mm) Thickness h (mm)
M4 4.3 9.0 0.8
M5 5.3 10.0 1.0
M6 6.4 12.0 1.6
M8 8.4 16.0 1.6
M10 10.5 20.0 2.0

Spring Lock Washer Dimensions (GB9074.26)

Thread Size Inner Dia. d₁ (mm) Outer Dia. d₂ (mm) Thickness s (mm) Width b (mm)
M4 4.1 7.1 0.9 1.5
M5 5.1 8.7 1.2 1.8
M6 6.1 10.2 1.6 2.0
M8 8.1 13.0 2.0 2.5
M10 10.2 16.2 2.5 3.0

Dimensional Data — GB9074.13 SEMS Screw (A2 Stainless Steel)

All dimensions in millimeters (mm). Bolt head dimensions per GB29.2. Nominal lengths per standard series.

Thread Size Pitch (mm) Head Width Across Flats s (mm) Head Width Across Corners e (mm) Head Height k (mm) Cross Recess Depth (mm) Min. Grip Length (mm) Nominal Length Range L (mm) Est. Unit Weight (g/pc) — M×16
M4 0.7 7 7.66 2.8 1.8 10 10–40 ≈ 1.5
M5 0.8 8 8.79 3.5 2.1 12 10–50 ≈ 2.8
M6 1.0 10 11.05 4.0 2.4 14 12–60 ≈ 4.8
M8 1.25 13 14.38 5.3 3.0 18 16–80 ≈ 10.5
M10 1.5 16 17.77 6.4 3.6 22 20–100 ≈ 19.0

Note: Unit weights are approximate reference values for L=16mm. Actual weight varies with nominal length. Contact FULLERKREG for precise weight data for your specific length requirement.

Product Gallery

Applications

GB9074.13 cross recessed hex SEMS screws are widely used across industries where assembly efficiency, vibration resistance, and corrosion resistance are critical:

  • ⚡ Electrical enclosures & control panels — secure panel covers, DIN rail brackets, and cable management components
  • 🖥️ Electronics & telecommunications equipment — chassis assembly, PCB mounting brackets, server rack hardware
  • 🏭 Sheet metal fabrication — HVAC ductwork, switchgear cabinets, industrial enclosures
  • 🚗 Automotive & transportation — interior trim panels, sensor brackets, lighting assemblies
  • 🔧 General mechanical assembly — wherever pre-assembled washers eliminate loose-part handling on production lines
  • 🌊 Marine & outdoor equipment — A2 stainless steel provides reliable corrosion resistance in humid and salt-spray environments

Why Choose FULLERKREG GB9074.13 SEMS Screws?

  • 🏭 Direct manufacturer — produced in-house to GB/T 9074.13-1988 standard with full dimensional traceability
  • 📦 Bulk wholesale supply — flexible MOQ, competitive pricing for OEM and MRO procurement
  • 📐 Strict dimensional control — 100% thread gauge inspection; washer captivation verified per standard
  • 📋 Material certification available — mill test reports and RoHS compliance documentation on request
  • 🚀 Fast lead times — standard sizes held in stock; custom lengths available with short lead times
  • 🌍 Global export experience — export packaging, ISPM-15 compliant crating, and international logistics support

Standard: GB/T 9074.13-1988 | Material: A2 Stainless Steel (SUS304) | Finish: Bright Passivated | Property Class: A2-70 | Brand: FULLERKREG

Sorry, this collection is empty.
Continue shopping