Product Specifications
| Model / Specification | 2# - 3/8 |
| Material | Carbon Steel |
| Nom. Dia. d |
2# | 3# | 4# | 5# | 6# | 8# | 10# | 12# | 1/4 | 5/16 | 3/8 | |
| d | Nom. Dia. | 0.0860 | 0.0990 | 0.1120 | 1.1250 | 0.1380 | 0.1640 | 0.1900 | 0.2160 | 0.2500 | 0.3125 | 0.3750 |
| dk | Max. | 0.167 | 0.193 | 0.219 | 0.245 | 0.270 | 0.322 | 0.373 | 0.425 | 0.492 | 0.615 | 0.740 |
| Min. | 0.155 | 0.180 | 0.205 | 0.231 | 0.256 | 0.306 | 0.357 | 0.407 | 0.473 | 0.594 | 0.716 | |
| k | Max. | 0.053 | 0.060 | 0.068 | 0.075 | 0.082 | 0.096 | 0.110 | 0.125 | 0.144 | 0.178 | 0.212 |
| Min. | 0.045 | 0.051 | 0.058 | 0.065 | 0.072 | 0.085 | 0.099 | 0.112 | 0.130 | 0.162 | 0.195 | |
| n | Max. | 0.031 | 0.035 | 0.039 | 0.043 | 0.048 | 0.054 | 0.060 | 0.067 | 0.075 | 0.084 | 0.094 |
| Min. | 0.023 | 0.027 | 0.031 | 0.035 | 0.039 | 0.045 | 0.050 | 0.056 | 0.064 | 0.072 | 0.081 | |
| t | Max. | 0.031 | 0.036 | 0.040 | 0.045 | 0.050 | 0.058 | 0.068 | 0.077 | 0.087 | 0.106 | 0.124 |
| Min. | 0.022 | 0.026 | 0.030 | 0.034 | 0.037 | 0.045 | 0.053 | 0.061 | 0.070 | 0.085 | 0.100 | |
Slotted Pan Head Tapping Screw Type C (Unified Thread) — Product Introduction
The slotted pan head tapping screw (Type C) is a self-tapping fastener with a pan head, a slotted drive, and a pointed tail. The “Type C” tail feature means the front end of the thread has a point. During installation, a pilot hole is pre-drilled in the base material, and when the screw is driven in, it relies on its own hardness to form a mating thread in the thin sheet by extrusion, completing the connection without a mating nut. This type of screw is produced according to ASME B18.6.4 (Unified Thread system), with specifications covering #2 to 1/2 inch. It is widely used for fastening connections between thin metal sheets.
1. Product Features
• Pan head and slotted drive structure: The head is a pan head (flat round head), and the drive is a slotted drive, which can be tightened with a flat-head screwdriver. The structure is simple and the cost is relatively low.
• Type C pointed design: The tail has a point, making positioning easy. When driven in, it can quickly cut into the base material, and can achieve self-tapping even in thin sheets (such as 0.5 mm).
• Unified thread system: Uses American Unified Thread (UNC/UNF). Thread specifications cover #2 to 1/2 inch, with threads per inch varying by specification.
• Full thread structure: The thread extends along the full length of the shank, suitable for thin sheet connection applications.
• Various materials and surface treatments: Common materials include carburized steel and stainless steel. Surfaces can be zinc plated and passivated, etc.
2. Product Advantages
• Convenient installation: No tapping or welding is required. After pre-drilling a pilot hole, the screw can be driven directly to form a mating thread, simplifying the assembly process.
• Accurate positioning: The Type C pointed design allows the screw to position quickly at the initial stage of driving, reducing the risk of assembly skew.
• Suitable for thin sheet connection: The self-tapping thread has a larger pitch and a larger contact area with the base material, providing reliable fastening force in thin sheet connections.
• Complete specification system: ASME B18.6.4 covers multiple specifications from #2 to 1/2 inch, facilitating selection and procurement.
3. Scope of Application
• Thin sheet metal connection: Suitable for fastening between steel sheets, aluminum sheets and other thin metal sheets. It is the most typical application scenario for self-tapping screws.
• Electronics and electrical appliances: Assembly of chassis, cabinets, control boxes and other sheet metal housings.
• General machinery and equipment: Connection points of various thin sheet structural parts, covers, and cover plates requiring quick assembly.
• Construction and decoration: Thin sheet fastening applications such as metal doors and windows, curtain walls, and metal decorative panels.
