Frequently used in the manufacturing industry and in machining operations, T-slot cutters take their name from the cutting tooth structure at the end of, or around, a cylindrical shank that resembles the letter T. They are generally preferred for machining T-slots, circlip grooves, dovetails (slideway seats) and special radius profiles on the inner or side faces of parts.
Watch Temak Teknik’s informative video below covering T-slot cutter types, angle types, material grades and application tips:
T-Slot Cutter Types and Designs
T-slot cutters are produced in different geometries according to the form to be machined and the type of operation:
1. Straight / Standard T-Slot Cutters
Used for cutting standard T-slots on machine tables, internal side grooves and circlip grooves. The teeth can be arranged staggered (angled) or symmetrically to distribute the cutting load.
2. Dovetail (Angled) Cutters
Used for machining the angled mating seats that slide within one another in slideway systems.
- Widely available in standard angles of 45° and 60°.
- Small-diameter models are produced with cylindrical shanks, while large-diameter models are mounted on arbor systems with a ground h7-tolerance bore and keyway.
- In addition to single-sided types, double-sided models that cut at an angle in both directions are also available.
3. Radius (Profile) T-Slot Cutters
Special profile cutters with a circular form, developed to machine concave or convex curved grooves in a single pass.
Material Grades and Mounting Systems
- HSS and HSS-Co (5% Cobalt): Thanks to their toughness and impact resistance, they are widely used on standard milling spindles and universal milling machines. The cobalt content provides additional resistance to heat and wear.
- Indexable (Carbide Insert) T-Slot Cutters: Allow higher cutting speeds on series-production CNC machines. However, as carbide inserts are hard and brittle, they are sensitive to impacts during cutting.
- Arbor-Mounted T-Slot Cutters: As diameter and width increase, arbor systems are used instead of making the tool in one piece. A keyway in the bore transmits the load.
Operational and Technical Tips
- Pre-Machining: Before machining with a T-slot or dovetail cutter, it is essential to pre-machine (rough out the initial slot) with a standard end mill or drill to reduce the chip load in the centre of the slot.
- Cutting Parameters: As the upper and lower faces of a T-slot cutter engage the material simultaneously when entering the part, high speeds and excessive feed should be avoided and a balanced feed rate applied.
- Versatile Use: T-slot cutters can be used not only on milling machines but also on lathes with driven tools for circlip grooving or special profile machining.