Turning Inserts
DCMT Carbide Turning Inserts
Positive 55° diamond turning inserts with a 7° clearance angle — a sharp, free-cutting edge that keeps cutting forces low for finishing, profiling, narrow grooves, aluminum and thin-wall parts.
Product Overview
DCMT inserts are positive 55° rhombic diamond indexable turning inserts with a 7° clearance angle (ISO 1832 D type) and a single-sided positive geometry. The positive rake gives a sharp, free-cutting action with noticeably lower cutting force than negative inserts, which makes DCMT a common choice for finishing and light semi-finishing of aluminum alloys, copper, brass, plastics and thin-walled components — and for machines with limited rigidity or long tool overhang. Each insert carries 2 cutting edges on one side. The sharp 55° corner reaches into narrow grooves, internal corners and profiling passes better than blunter 60° or 80° shapes. Compared with positive TCMT inserts (60° triangle, 3 edges), the 55° DCMT corner is more pointed, giving better access to tight corners and narrow slots, while TCMT offers a stronger corner for general finishing; compared with negative DNMG inserts (0° clearance, two-sided, 4 edges), the positive DCMT edge is sharper and cuts with less force, but the geometry is not as strong, so DCMT is best matched to finishing work while DNMG handles heavier roughing. Available in standard ISO sizes DCMT070202 / 070204 / 070208 and DCMT11T304 / 11T308.
Key Features
- 2 cutting edges per insert — single-sided positive geometry with 7° clearance
- Sharp positive rake gives a free-cutting action with low cutting force and less heat generation
- Pointed 55° corner reaches narrow grooves, internal corners and profiling features that blunter shapes cannot access cleanly
- Excellent surface finish on aluminum alloys, copper, brass and plastics without edge build-up at correct speeds
- Low cutting force suits thin-wall tubes, slender shafts and low-rigidity machines or long overhang setups
- PVD-coated and uncoated grades with sharp edge hone, optimized for finishing passes
- Complements positive TCMT (3 edges, stronger corner) and negative DNMG (4 edges, heavier cuts) in the same program
- Full size range: DCMT0702 (1/4" IC) and DCMT11T3 (3/8" IC) series
- Custom grades and private-label packaging available
Applications
Factory-direct — produced in our own carbide plant
ISO 1832 dimensional compliance, batch inspected
OEM / ODM support for distributors and brands
Application support for grade and parameter selection
Technical Specifications
| Item | Specification |
|---|---|
| Insert Shape | 55° rhombic diamond (D type), positive geometry, single-sided |
| Clearance Angle | 7° (C type, positive rake) |
| Standard Sizes | DCMT070202 / DCMT070204 / DCMT070208 / DCMT11T304 / DCMT11T308 (ISO 1832) |
| Inscribed Circle (IC) | 6.35 mm (07 series, 1/4"), 9.525 mm (11T3 series, 3/8") |
| Thickness (S) | 2.38 mm (07 series), 3.97 mm (11T3 series) |
| Nose Radius (r) | 0.2 / 0.4 / 0.8 mm |
| Cutting Edges | 2 per insert (single-sided) |
| Coating | PVD (TiN / TiAlN) / Uncoated |
| Applications | Finishing & light semi-finishing: external & internal turning, facing, profiling, narrow grooves, thin-wall boring |
| Workpiece Materials | Aluminum alloys, copper, brass, plastics, mild steel, stainless steel (finishing) |
| MOQ | 10 pcs (standard sizes) |
| Lead Time | 3-7 days standard, 15-30 days custom |
* Specifications subject to change. Contact us for the current datasheet.
FAQ
Questions Buyers Ask
What does DCMT stand for?
Per ISO 1832: D = rhombic diamond shape with a 55° included angle, C = 7° clearance angle (positive geometry), M = tolerance class (medium), T = chip breaker / clamping design. For example, DCMT070204: inscribed circle 6.35 mm, thickness 2.38 mm, nose radius 0.4 mm.
What is the difference between DCMT and DNMG inserts?
Both are 55° diamond shapes, but the geometry is different. DCMT is a positive insert (7° clearance, single-sided, 2 cutting edges) with a sharp edge that cuts with low force — ideal for finishing aluminum, copper, plastics, thin-wall parts and low-rigidity machines. DNMG is a negative insert (0° clearance, two-sided, 4 cutting edges) with a stronger edge for heavier roughing of steel and cast iron. They are complementary: use DCMT for finishing and light cuts, DNMG for roughing and heavy depths of cut.
What is the difference between DCMT and TCMT inserts?
Both are positive inserts with a 7° clearance angle and single-sided geometry. DCMT is a 55° diamond with 2 cutting edges; TCMT is a 60° equilateral triangle with 3 cutting edges. The pointed 55° DCMT corner gives better access to narrow grooves, internal corners and profiling features, while the 60° TCMT corner is a little stronger for general finishing. Many shops stock both and use DCMT for detail work and TCMT for broader finishing passes.
Which workpiece materials are DCMT inserts best for?
DCMT inserts perform best on aluminum alloys, copper, brass, plastics and other soft, non-ferrous materials, and for finishing passes on mild steel and stainless steel. Because the positive edge is sharper but less strong than a negative insert, it is not the first choice for heavy roughing of steel or cast iron — that is the job of DNMG or CNMG negative inserts.
Which nose radius should I choose — 070202, 070204, 070208 or 11T304, 11T308?
The last two digits are the nose radius: 02 = 0.2 mm (fine finishing, small parts, low cutting forces), 04 = 0.4 mm (general finishing), 08 = 0.8 mm (stronger edge, semi-finishing and light roughing). For most finishing work, DCMT070204 or DCMT11T304 is a good starting point.
Do DCMT inserts fit my existing tool holders?
Yes — DCMT inserts fit standard positive 55° diamond tool holders and boring bars for the same ISO seat, such as SDJCR / SDJCL boring bars and matching positive holders for the 07 (1/4" IC) and 11T3 (3/8" IC) sizes. Check the holder seat designation against the insert size and you can drop them in without changing setup.
Do you offer private label for DCMT inserts?
Yes — OEM/ODM with private-label packaging, custom grades and laser marking per your specification. Standard sizes MOQ 10 pcs.
APPLICATIONS
Where It's Used
Typical machining operations and workpiece materials for DCMT Carbide Turning Inserts. Contact us with your operating parameters for grade selection support.
Finishing and light semi-finishing of aluminum alloy components
Profiling and contouring where the 55° corner shape improves access and clearance
Narrow grooves, slots and internal corners that need a pointed edge
Thin-wall tubes, sleeves and rings where low cutting force prevents deflection
Small-bore internal finishing with the DCMT0702 series
Finishing passes on mild steel and stainless steel after roughing with negative inserts
Interested in DCMT Carbide Turning Inserts?
Factory-direct pricing, OEM/ODM options and lead times — send your spec and volume, get a quote within 24 hours.