DCMT 070204 Chip Breaker BF Grade FM2553 / DCMT 21.51 BF #FMCarbide

DCMT 070204 / DCMT 21.51, chip breaker BF, grade FM2553 — positive 55° rhombic turning insert.

1/4" inscribed circle, 3/32" thick, 1/64" corner radius. The BF breaker is the Finishing geometry: 0.002–0.008 ipr (0.05–0.2 mm/rev) at 0.02–0.06" (0.5–1.5 mm) depth of cut. FM2553 is a CVD (Al₂O₃) grade — tough substrate for heavy interrupted cuts in steel and stainless, heavy roughing in mild steel, and first choice for superalloys.

Specifications

• Insert designation (ISO): DCMT 070204
• Insert designation (inch): DCMT 21.51
• Insert shape: 55° rhombic (D)
• Clearance angle: 7° (C)
• Tolerance class: M
• Insert type: T — with hole, countersunk one side, chipbreaker one side
• Inscribed circle (I.C.): 1/4" (6.35 mm)
• Thickness: 3/32" (2.38 mm)
• Corner radius: 1/64" (0.4 mm)
• Chip breaker: BF — Finishing
• Feed rate range: 0.002–0.008 ipr (0.05–0.2 mm/rev)
• Depth of cut range: 0.02–0.06" (0.5–1.5 mm)
• Grade: FM2553
• Coating: CVD (Al₂O₃)
• ISO application range: P20–P35 · M10–M30
• Cutting speed, non-alloy steel: 490–1150 SFM (150–350 m/min)
• Cutting speed, low-alloy steel: 300–980 SFM (90–300 m/min)
• Cutting speed, high-alloy steel: 230–820 SFM (70–250 m/min)
• Cutting speed, ferritic & martensitic stainless: 390–750 SFM (120–230 m/min)
• Cutting speed, austenitic stainless: 260–660 SFM (80–200 m/min)
• Cutting speed, titanium & super-alloys: 110–260 SFM (35–80 m/min)

TURNING KNOW-HOW

Get more from your turning inserts.

Practical guides to choosing, understanding and using your inserts.

01 / SELECTION

Grades & chip breakers

Explore the grade and chip-breaker selection chart for your turning operation.

Explore the chart → 02 / INSERT CODES

Know your insert

Understand turning-insert designations and what the letters and numbers mean.

Read the guide → 03 / CUTTING PARAMETERS

Turning calculations

Learn how to use a turning formula calculator to work through the numbers.

Explore the formulas →