Whenever you're sewing particularly dense or difficult fabrics--especially synthetics--or sewing at high speeds, heat can build up in your sewing machine needle. Your needle will break easier because the steel will be "detempered" byt he heat, and you may experience more thread breakage because your thread becomes more brittle as it passes through the hot needle eye.

Try coating the needle with silicone thread lubricant prior to its passing through the needle. Some people do this by soaking whole cones of thread in lubricant overnight. A more efficient method is to attach a thread lubricator box (via its built-in magnet) to the machine head somewhere along the path of the thread. The thread passes through the box over a sponge inside and picks up lubricant before it passes through the needle, helping keep both the needle and the thread cooler.

For the same purpose, some sewing machine needles are available with a Teflon or similar coating to reduce heat build-up. These are not showing on our web site but we can quote them to you.