Blind hole machining requires attention to detail to attain desired outcomes. Here are some helpful considerations for effective blind hole drilling.
Choosing the Right Bits and Taps
Choose the appropriate bit that matches the material you want to machine. Expert machinists often recommend using high-speed steel to create threads in most metals.
In addition, ensure the tap radius corresponds with the preferred thread size to achieve a precise threaded blind hole. Depending on the blind hole depth, consider whether the type of tap, either a plug, taper, or bottoming tap, is the right fit for threading the blind hole.
Drill Depth Clearance
Measure and mark the desired depth on the drill bit to avoid drilling overly deep cavities because it weakens the material and increases the risk of material breakage. You can also control the drilling process using adjustable depth collars or depth stops on the drill press.
More importantly, consistently checking the depth clearance before drilling will help to prevent damage to the workpiece. Also, refer to design specifications to drill blind holes of the correct depth.
Hole Placement and Orientation
Hole placement and orientation influence the manufacturability and usefulness of parts significantly. To accurately drill blind holes, mark the holes’ locations with layout tools such as layout squares and center punches. As you drill blind holes, ensure their orientation matches the desired function of the final product or assembly, allowing smooth integration for designs.
Hole Diameter
The required hole diameter will determine the ideal drill bit size. The drill bit chart is a reliable reference for choosing a suitable drill bit size for the hole. Also, ensure to test the fit of the bit in scrap material before drilling the final blind hole.
Clean Blind Holes
Use the appropriate cutting fluid or lubricant to reduce heat buildup and friction during drilling. Use a cleaning brush or compressed air to extract debris from the blind hole. However, it is crucial to inspect the blind hole and confirm it is clean and clear before tapping it.
