If you’re not familiar with what a reamer is, all you need to know is that it’s a rotary cutting tool mainly used in metalworking. They come in two kinds – precision and non-precision. Precision reamers give you a nice smooth finish to holes and are very accurate, hence their name. Non-precision reamers are ideal if you simply need to enlarge an existing hole and don’t need a great finish or to get rid of burrs or unwanted imperfections.
Reamers can be adjustable or fixed, handheld or machine compatible, and there are few different finishes available, including tapered reamers for different uses. Handheld reamers work best with wood or plastic while machine reamers are better for harder materials such as metal.
To drill accurate holes with a reamer, select the size you want first – you can normally buy a set of reamers with a good choice of sizes so you should be able to find what you need easily enough. Sometimes you might need to select a reamer slightly undersize to the one you want if you need a really tight finish. Reamers can be slightly flexible and the pilot hole you’ll need to drill into could be not completely round or a touch out of position. Going a size down allows for manufacturing tolerances and vibrations in the drilling process.
When you attach your reamer don’t ram it in tightly. Instead let if ‘float’ so it can move a bit as this will give you better accuracy. Consider your speed too. The faster you drill with the reamer, the more movement there’ll be and the more heat generated. Going slowly will give you better control so you can get a lovely smooth finish. Aligning your reamer up with the pilot hole will be much easier too if you go nice and slow. There’s nothing worse than an over-sized hole caused by a wobbly reamer.
Use a vice or clamps when using a reamer too for extra support and keep whatever you’re drilling nice and still. Always drill a pilot first as a reamer is for enlarging not drilling. Clean the hole before reaming so it’s not full of filings and bits of rubbish. And use lubricant if you need to. Very hard materials are easier to ream with specialist lubricant, and they’ll help keep the reamer cool as well.
Blog Uploaded: 12th January 2016