The Turning Holder you decide to go with depends on the type of parts you will be machining.
- If it is medium to larger parts then there are holders for Negative Inserts that are double sided like a CNMG43_ that are the strongest and most popular for roughing and give you more economy on the inserts as you get double the cutting edges.
- If it is smaller parts then there are holders for Positive Inserts that are single sided like a CCMT21.5_ or a DCMT32.5_ that will be less tool pressure and freer cutting. These OD Turning Holders can also be used in Boring Bars 3/8” Diameter Shank and up
Negative Insert Holders:
The 80° CNMG43_ Insert is the most common and popular insert in OD Turning. The 80 degree angle makes this a strong insert and the insert is held rigidly in the holder. Plus you can Turn and Face in a Standard Holder. This is our first choice for OD Roughing on a CNC Lathe as it is strong and there are many insert options. This DCLNR Holder is available for 3/4" Square Shank Holders and up as well as Boring Bars ¾” Shank and up.
*DCLNR and DCLNL Holder
The 80° WNMG43_ Insert is also popular for OD Turning. The Trigon Shape gives you 6 cutting edges compared to 4 cutting edges on a CNMG43_ Insert giving you much better economy at a similar insert price. If you are doing heavy roughing or have more critical dimensions you need to hold then the CNMG Insert is a better choice as there is more steel on the holder supporting a CNMG Insert compared to a WNMG Insert (shown below). But in most applications the WNMG is plenty rigid! The DWLN Holder is available for ¾” Square Shank Holders and up.
*DWLNR (RH) and DWLNL (LH) Holder
If you are machining long shafts are looking to reduce tool pressure then a great option is a 55° DNMG43_ Insert. If you run into chatter or tool pressure issues on a part then the best way to fix it is by lowering the engagement angle or go with a Positive Single Sided Insert instead of a Negative Double Sided Insert. The 55° angle of the DNMG Insert is a lot less tool pressure than the CNMG or WNMG Inserts above and is our first choice if tool pressure is going to be an issue or if you need to do profiling or undercutting in OD Turning. The DDJNR and DDHNR Holders are available for ¾” Shank Holders and up.
*DDJNR (RH) and DDJNL (LH) Holder, DDHNR (RH) and DDHNL (LH) Holder
If you need to reduce tool pressure even more or have a lot of profiling to do on a part then a 35° VNMG33_ Insert is the best option. This insert is less tool pressure than a DNMG Insert and comes in 3 different holder options that allow you to OD Profile at all angles. The DVJNR, DVPNR and DVVNN Holders are available for ¾” Shank Holders and up.
*DVJNR (RH) and DVJNL (LH) Holder, DVPNR (RH) and DVPNL (LH) Holder, DVVNN (Neutral) Holder
Positive Inserts:
*All Positive Inserts are available in a Molded Cutting Edge (the 3rd Letter in the description is M) and Ground Cutting Edge (3rd letter is G). The Molded Cutting Edge is stronger for roughing and these inserts are less expensive. The Ground Cutting edge is sharper for finishing or to reduce tool pressure and the inserts are a little more as there is another operation on these inserts to grind the cutting edge.
The SCLCR/L 80°Holder for CCMT21.5_ and CCMT32.5_ Inserts (as well as CCGT21.5_ and CCGT32.5_ Inserts, CCMT and CCGT are the same geometry, the M stands for Molded Cutting Edge and the G stands for Ground Cutting Edge). This is the strongest insert geometry for positive inserts that go up to a square shoulder and can also be used on your boring bars (3/8” Shank and up for CCMT21.5_ Inserts as well as ½” Shank and up for CCMT32.5_ Inserts). This Holder is popular in smaller shank machines as well as Swiss Machines and is available from 3/8” Shank and up.
*SCLCR (RH) and SCLCL (LH) Holder
The SDJCR 55° Holder for DCMT21.5_ and DCMT32.5_ Inserts (as well as DCGT21.5_ & DCGT32.5_ Inserts) is the most popular Geometry for Swiss Machines. The 55° angle makes this a free cutting insert that is capable of profiling at different angles as well as turning up to a square shoulder. Plus the DCMT and DCGT Insert lineup gives you the most options of chipbreakers/grade and radius options.
*SDJCR (RH) and SDJCL (LH) Holder, SDXCR (RH) and SDXCL (LH) Holders, SDNCN (Neutral Holders)
The SVJBR Holder for VBMT22_ and VBMT33_ (as well as VCMT22_ and VCMT33_ Inserts. The VBMT has a 5° Side Rake Angle while the VCMT has a 7° Side Rake Angle so a VCMT fits into a VBMT Holder with no issues) is great for profiling into tighter angles or at a deeper depth than a DCMT Insert and will also lower tool pressure.
*SVJBR (RH) and SVJBL (LH) Holders as well as SVPBR (RH) and SVPBL (LH) and SVVBN (Neutral) Holders
