GB/T 5267.1 is the standard cited for cross flat-head knurled self-tapping screws. This page sets out what the standard controls for this part, reproduces the dimensional table supplied against it, and notes the related designations referenced on drawings.
GB/T 5267.1 — Scope
GB/T 5267.1 specifies the dimensional requirements for cross flat-head knurled self-tapping screws.
Material, surface condition and any performance rating are set by separate documents specific to this part family — ISO 898-1 and ISO 898-2, which govern bolt and nut property classes, do not apply here.
Tolerance & Product Grades
Tolerances for cross flat-head knurled self-tapping screws are given as limits on the individual dimensions in the table rather than as a fastener product grade.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by GB/T 5267.1
| Head form | Under-head feature | Material | Finish options | Substrate |
|---|---|---|---|---|
| cross-recess flat head | under-head knurling | carbon steel | zinc plating | wood |
| cross-recess flat head | under-head knurling | carbon steel | colour zinc plating | plastic |
| cross-recess flat head | under-head knurling | carbon steel | black oxide | thin plate |
Companion Standards
GB/T 5267.1 controls only the geometry of cross flat-head knurled self-tapping screws. Surface finish is governed by separate finish standards (for example ISO 4042 for electroplating), and corrosion testing by ISO 9227 (neutral salt spray). Mechanical performance is set by the standards specific to this part family, not by ISO 898-1 or ISO 898-2, which apply to bolts, screws and nuts.
When to Specify GB/T 5267.1
Choose GB/T 5267.1 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for cross flat-head knurled self-tapping screws.
