Product Specifications
| Model / Specification | M1.6 – M10 |
| Material | Carbon Steel |
| Thread Size d |
M1.6 | M2 | M2.5 | M3 | (M3.5) | M4 | M5 | M6 | M8 | M10 | ||
| P | Pitch | 0.35 | 0.4 | 0.45 | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 | 1.5 | |
| a | Max | 0.7 | 0.8 | 0.9 | 1 | 1.2 | 1.4 | 1.6 | 2 | 2.5 | 3 | |
| b | Min | 25 | 25 | 25 | 25 | 38 | 38 | 38 | 38 | 38 | 38 | |
| dk | Theoretical | Max = Nominal | 3.6 | 4.4 | 5.5 | 6.3 | 8.2 | 9.4 | 10.4 | 12.6 | 17.3 | 20 |
| Actual | Max = Nominal | 3 | 3.8 | 4.7 | 5.5 | 7.3 | 8.4 | 9.3 | 11.3 | 15.8 | 18.3 | |
| Min | 2.7 | 3.5 | 4.4 | 5.2 | 6.94 | 8.04 | 8.94 | 10.87 | 15.37 | 17.78 | ||
| k | Max = Nominal | 1 | 1.2 | 1.5 | 1.65 | 2.35 | 2.7 | 2.7 | 3.3 | 4.65 | 5 | |
| n | Nominal | 0.4 | 0.5 | 0.6 | 0.8 | 1 | 1.2 | 1.2 | 1.6 | 2 | 2.5 | |
| Max | 0.6 | 0.7 | 0.8 | 1 | 1.2 | 1.51 | 1.51 | 1.91 | 2.31 | 2.81 | ||
| Min | 0.46 | 0.56 | 0.66 | 0.86 | 1.06 | 1.26 | 1.26 | 1.66 | 2.06 | 2.56 | ||
| r | Max | 0.4 | 0.5 | 0.6 | 0.8 | 0.9 | 1 | 1.3 | 1.5 | 2 | 2.5 | |
| t | Max | 0.5 | 0.6 | 0.75 | 0.85 | 1.2 | 1.3 | 1.4 | 1.6 | 2.3 | 2.6 | |
| Min | 0.32 | 0.4 | 0.5 | 0.6 | 0.9 | 1 | 1.1 | 1.2 | 1.8 | 2 | ||
| x | Max | 0.9 | 1 | 1.1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3.2 | 3.8 | |
| Wt/1000 Pcs (Steel) ≈ kg | - | - | - | - | - | - | - | - | - | - | ||
| Thread Length b | - | - | - | - | - | - | - | - | - | - | ||
Slotted Countersunk Flat Head Screw— PRODUCT INTRODUCTION
Also known as slotted flat head screw or flat head machine screw, the countersunk flat head screw is a standard fastener featuring a tapered head with a straight slot (single-dimension slot) on the top face. The head taper angle is typically 90°, allowing the screw to be fully countersunk into the mating surface after installation, creating a smooth, flush appearance with no protrusion. Sizes range from M1.2 to M20. Main materials include carbon steel (Grade 4.8) and stainless steel (A2-70). It is one of the most fundamental general-purpose fasteners.
I. PRODUCT FEATURES
Countersunk tapered design: The 90° conical head mates with the countersunk hole in the workpiece, allowing the screw head to be fully embedded with the surface flush and level.
Slotted drive: A single straight through-slot on the top of the head can be driven with a standard flat-blade screwdriver, offering maximum tool compatibility.
Full thread construction: Standard type features full thread running from directly below the head to the tip, with no plain shank section.
Wide size range: Standard sizes available from M1.2 micro screws to M20 medium-duty screws.
II. PRODUCT ADVANTAGES
Smooth and aesthetically pleasing installation: The countersunk design keeps the screw head flush with the surface, meeting flush appearance requirements and avoiding scratches or snagging.
Simple tool compatibility: The single slot is the most basic drive type — no special wrench needed; a single screwdriver handles both installation and removal.
Exceptional versatility: As a basic standard component, it features unified specifications, excellent interchangeability, and ample market supply.
Cost-effective: Simple structure and mature manufacturing process make it one of the most economical screw types available.
III. APPLICATION AREAS
Wood products and furniture: Countersunk fastening for hardware such as hinges, drawer slides, and locks.
Architectural hardware: Flush-mount installation for door and window handles, baseboard clips, and switch plates requiring a smooth surface finish.
Electronics and appliances: Fastening for switches and sockets, terminal blocks, and small instrument enclosures where high torque resistance is not required.
General machinery: Connections for cover plates, guards, nameplates, and other components that are infrequently disassembled and have moderate clamping force requirements.
