Parting and Grooving Inserts – TDJ and TDXU Blades

Parting off is the operation that breaks the most inserts and wastes the most material, and almost every one of those failures traces back to the same handful of causes. Dhankuber Traders stocks TDJ and TDXU parting and grooving blades in 2 mm, 3 mm and 4 mm widths, and the guidance below will get more life out of whichever one you buy.

Inserts We Stock

• TDJ 2 – 2 mm width, double ended so you get two cutting edges per insert. The narrowest of the three and therefore the least wasteful in material, but also the most sensitive to setup.
• TDJ 3 – 3 mm width, double ended. The general purpose parting width for medium diameter bar work, with noticeably more edge strength than the 2 mm.
• TDXU 4 – 4 mm width. For larger diameter parting and wider grooves where the extra blade strength is needed to reach depth without deflection.

Choosing the Width

Narrower is not automatically better. The width has to be balanced against the depth you need to reach.

• 2 mm – smallest kerf, so the least material wasted per cut. Best on small diameter bar with a short reach. Deflects if you push it deep.
• 3 mm – the default for most bar work. Enough blade strength to reach a reasonable depth without wandering.
• 4 mm – for larger diameters where the blade has to reach a long way in. The wider blade resists deflection, which is what actually determines whether the cut stays straight.

The working rule is to select the narrowest width that can reach your parting depth without deflecting. Material saved on kerf is worth nothing if the blade wanders and scraps the part.