Malco BT133-100 Hex Washer Bit-tip Screw 100 Pack

Product Description

The MALCO BT133-100 is a hex washer head bit-tip screw designed for sheet metal and light-gauge steel fastening applications. Each screw measures No. 8 diameter by 3/4 inches in length, features 18 threads per inch (TPI), and is driven with a 1/4-inch hex drive. The integrated No. 2 drill point eliminates the need for a separate pilot hole, producing an optimum hole size for better thread engagement and a tighter fit. Screws are cold forged for consistent dimensional uniformity and precise drill point contour. Heat-treated steel construction provides reliable holding strength across a wide range of field conditions. This bulk pack contains 100 screws.

These bit-tip screws are suited for HVAC duct fabrication, sheet metal assembly, and light structural fastening where self-drilling capability saves time and reduces the need for auxiliary equipment such as drill bits or welding setups. The 1/4-inch hex drive makes them compatible with standard power screwdrivers and magnetic hex nut drivers commonly used by HVAC technicians and sheet metal workers. The hex washer head provides a wide bearing surface and positive drive engagement on metal substrates.

Key Features

• No. 2 drill point produces an optimum pilot hole for improved thread engagement and holding strength
• Cold-forged construction ensures uniformity of dimensions and drill point contour across the full 100-piece bulk pack
• Heat-treated steel for added hardness and durability in demanding fastening applications
• Hex washer head provides a wide bearing surface and resists cam-out during installation
• 1/4-inch hex drive is compatible with standard power drivers and nut drivers
• Eliminates the need for separate drill bits or welding equipment, reducing setup time on the job

Compatibility

Designed as an OEM-style self-drilling fastener for sheet metal and light-gauge steel applications commonly encountered in HVAC duct work and metal fabrication installations.

Installation Notes

Installation is typically performed by HVAC technicians or sheet metal workers using a 1/4-inch hex drive power screwdriver or drill. Ensure the work material is secured before driving screws to prevent movement that could affect thread engagement. Do not overdrive — excessive torque can strip threads or damage the hex washer head bearing surface. Follow applicable mechanical and building codes for fastener spacing and load requirements.

Technical Specifications

• Nominal Diameter: No. 8
• Length: 3/4 inches
• Threads Per Inch (TPI): 18
• Drive Style: 1/4 inch Hex
• Head Style: Hex Washer
• Drill Point Size: No. 2
• Material: Steel
• Process: Heat Treated
• Quantity: 100 per Bulk Pack
• Warranty: Lifetime Limited

Standard Information

• Brand: MALCO
• Manufacturer Part Number: BT133-100