The finish has PTFE (like Teflon) that helps reduce friction and the resulting heat. Vortex needle coolers use cold compressed air to further cool needles

135x53 CS type needles have a round top (no flat side) for industrial upholstery and walking foot machines.

Less Thread Breakage, Less Sticking, Less Downtime.
The CS Cool-Sew finish on the needle surfaces and in the needle’s eye is resistant to sticking. Its finish has a very low friction coefficient, which prevents excessive heat buildup and resulting problems. Few, if any, materials stick to the surfaces of Cool-Sew needles. Cool-Sew needles are ideal for stitching through vinyl, synthetics, chemically treated materials, glued materials, rubberized goods, nylon, foam, dense materials, and with synthetic threads. When Cool-Sew needles are used under conditions described above you can expect neater stitches, less sewing thread breakage, less puckered stitches, less downtime, less defects, and increased productivity.

Regular needles show buildup of sticking fibers while Cool-Sew needle is free of buildup.

As synthetic threads pass through the eye of a needle, they create friction and heat which may melt or snap threads. In some cases, the eye of the needle may be cut. The COOLSEW finished needle eye acts as if eye is lubricated and thereby alleviates the aforementioned problems. As an ordinary chromium plated needle penetrates through synthetic materials, the materials may stick to the needle. This may cause some of the synthetic materials to pass through the needle holes and create undesirable finishes. The sticking to the surface of the needle may also create heat-buildup problems such as melting and machine jamups. The COOL-SEW finish on the needle helps alleviate the sticking and heat-buildup problems.