The following is a detailed description of the custom requirements for national standard stainless steel pan head washer machine screws with hexagonal half-thread screws. The content is both professional and practical.
I. Core Parameter Requirements
Standard Reference
National Standard: GB/T 818-2016 (pan head screws) or GB/T 70.1-2008 (hexagon socket screws; if a hexagonal socket is required, this can be adjusted to meet customer requirements).
Material Standard: GB/T 1220-2007, which also specifies stainless steel materials.
Material and Properties
Stainless Steel Grade: A2-70 (304 stainless steel) or A4-80 (316 stainless steel) (corrosion resistance grade must be specified).
Mechanical Properties: Tensile Strength ≥ 700 MPa (A2-70), Hardness HRC 22-32.
Surface Treatment: Natural passivation or electroplating, but specified coating required.
Specifications
Head Type: Pan head with integrated flat washer.
Groove Type: Torx, Common Specifications: T20/T25/T30.
Thread Type: Metric Coarse Thread.
Length: Indicated as Full or Half Thread.
Tolerances and Certifications
Thread Tolerance: 6g (National Standard).
Certification Requirements: ROHS, SGS, etc., available (additional fee required).
II. Customization Details
Special Requirements
Non-standard Dimensions: For example, increases or decreases in head diameter or washer outer diameter.
Locking Lock: Nylon adhesive or double-stacked washers are available.
Marking: Whether the head needs laser marking.
Packaging and Delivery
Packaging: Blister Tray/Roll Packing/Bag Packing.
Delivery Time: 3-7 days for samples, 15-30 days for mass production (depending on quantity).
MOQ: Minimum Order Quantity: 5,000 pieces (small orders incur a surcharge).
III. Notes
Material Substitutions
316 stainless steel is relatively expensive. 304 can be used instead if there is no strong acid environment. For high strength requirements, 12.9 grade alloy steel (rustproofing required) can be used.
Groove Compatibility
Torx grooves require matching tools. For versatility, Phillips grooves can be used.
Document Submissions
Drawings or 3D models (STEP/IGS format) are required to confirm details. A technical agreement must be signed to clearly define acceptance criteria.
