No.8 (4.2mm) x 3/8 inch (9.5mm) Pozi Pan Head Thread Cutting Screws Type BT (BS 4174) - Steel - Bright Zinc Plated Description
The No.8 (4.2mm) x 3/8 inch (9.5mm) Pozi Pan Head Thread Cutting Screws Type BT (BS 4174) - Steel - Bright Zinc Plated has the following features:
- Drive Size: PZ2
- Bright Zinc Plated Finish
- For Use With: Suitable for Use With Plastics and Other Low Density Materials
- Head Diameter (D): 8.18 mm
- Head Diameter (D) Tolerance: +0/-0.41 mm
- Head Height (H): 2.92 mm
- Head Height (H) Tolerance: +0/-0.25 mm
- Manufacturing Standard: BS 4174
- Steel
- Steel Material Family
- Nominal Length (L): 3/8 inch (9.5 mm)
- Pilot Hole Size: 3.5 mm
- Thread Pitch: 18 TPI
- Thread Size: No.8 (4.2 mm)
- Thread Type: Type BT
Discover more about the BT Thread Profile Pozi Pan Head Thread Cutting Screws range.
BT thread profile pozi pan head thread cutting screws are specialised precision fasteners engineered to cut their own threads into plastic substrates, reducing the risk of damage. Manufactured to BS 4174 standards, they feature a unique 'BT' thread profile that prevents the splitting or bulging often associated with standard self-tapping screws.
With a flat Pan Head for even load distribution and a Pozi drive for superior torque transmission, these self-tapping screws for plastic provide a secure, high-quality solution for modern plastic assemblies.
How BT Thread Profile Pozi Pan Head Thread Cutting Screws Work
These BT thread profile Pozi pan head screws operate with their unique thread profile, slicing cleanly into the plastic material rather than displacing it. This significantly reduces radial stress within the boss to prevent cracking in brittle or rigid plastics. This capability of the BT thread eliminates the need for a separate tapping process, allowing engineers to drive the screw directly into moulded pilot holes for rapid assembly.
In a real-world engineering context, these screws are indispensable in the assembly of consumer electronics, such as securing the outer casing of a router or gaming console. An engineer can drive the screw directly into a moulded pilot hole; the screw cuts a clean thread, creates a high-strength joint and ensures the delicate plastic housing remains intact.
Materials BT Thread Profile Pozi Pan Head Thread Cutting Screws Are Made From
To ensure optimal performance and longevity, our range of BT thread profile Pozi pan head screws is manufactured from:
- Steel with Bright Zinc Plating (BZP): High-grade steel provides the tensile strength needed for installation, while the bright zinc plating serves as a durable protective shield. This finish prevents the underlying metal from rusting and offers a clean, professional aesthetic, making it ideal for interior applications or assemblies not exposed to harsh outdoor elements.
Sizes and Types of BT Thread Profile Pozi Pan Head Thread Cutting Screws Available
Accu’s range is stocked in thread sizes ranging from No.4 (2.9mm) for intricate electronic applications, up to No.10 (4.8mm) for heavier-duty plastic fastening. Lengths range from 1/4 inch (6.5mm) to 3/4 inch (19mm) to accommodate various material thicknesses.
All components in this range are strictly manufactured in accordance with BS 4174, ensuring consistent tolerances and predictable performance for your critical projects.
FAQs
Q: What is the difference between a thread-cutting screw and a thread-forming screw?
A: Thread-cutting screws, like the BT profile, physically remove material to create a thread, much like a tap. Thread-forming screws displace material to create the thread. Thread cutting is generally preferred for brittle or rigid plastics to prevent the material from cracking under stress.
Q: Do I need a pilot hole for BT thread profile screws?
A: Yes, a pre-drilled or moulded pilot hole is required. The size of the hole depends on the hardness of the plastic and the size of the fastener. Harder plastics generally require slightly larger pilot holes to facilitate the cutting action without excessive torque.
Q: Can BT thread profile Pozi pan head thread cutting screws be used on metal?
A: These screws are specifically designed for use in plastics. While hardened steel thread cutting screws exist for metal, the BT profile is optimised for the density and characteristics of plastic materials. Using them in metal may damage the screw threads or fail to cut effectively.
