Juego de brocas cuadradas para carpintería, brocas de avellanador de cincel de mortajar de madera HSS, juegos de herramientas eléctricas para sierra de agujero para carpintero, 1/4, 5/16, 7/16, 1/2, 5/8 pulgadas, juego de 5

Attention: When you use these square drill bits, please make sure that the drill bit and the board are at a 90 degree angle to avoid the center drill bit from breaking How to instatll these square drill bits? 1, The drill core is very sharp. Wear working gloves to avoid direct contact between your hands and the drill bit during installation. 2, Put the square drill shell and drill core into the jig of the square tenoning machine, and then hold the square hole drill bit by hand 3, Take 0.5~1mm thick sheet (metal sheet or plastic sheet) and jam it at the step of the drill shell. After fixing the drill core, remove the sheet, then adjust the angle of the drill shell to the top to ensure clamping, so that a 0.5~1mm gap can be formed between the drill core head and the inner bevel of the drill shell, which can prevent the bit from jamming during use .Features: Suitable for construction, installation, renovation, decoration industry, etc. Ground and Hardened high speed steel for efficient performance and long life Apply for woodworking project,construction,installation,decoration industry Specification: Material: High Speed Steel(HSS) Hardness: Up to HRC48~50 Size: Square hole, 1/4"(6.4mm), 5/16"(8mm), 7/16"(11mm), 1/2"(12.7mm), 5/8"(16mm). Corresponding shank, 7/40"(4.4mm), 2/9"(5.8mm), 10/31"(8.2mm), 3/8"(9.8mm), 3/8"(9.8mm). More details please check the second picture and it is more intuitive. Shape of hole: square, rectangle Suitable for bench drilling machine, mortising machine or a mortising attachment, But not for any hand drillPackage included: 5Pcs woodworking chisel drill bits