90° Square Shoulder Insert Grades and Selection Guide
| Shock & Wear Resistance | Uncoated (Base Grade) | with Coating | Description | Specifications |
|---|---|---|---|---|
| TOUGHEST Shock Resistance |
DMP35 | Moderate wear resistance/high shock resistance. Recommended for interrupted or unstable steel applications, most stainless steel and high-temperature alloy applications. | ANSI C1-C2, ISO K25-K40, M25-M35 | |
| DMP353 | PCD TiCN – low to medium-temperature applications. | |||
| DMP35-HP | PVD AlCrN – premium low- to medium-temperature coating. Best when coolant is required. | |||
| NEW | DMP35-TCI | Modified AlTiN – premium medium- to high-temperature coating. | ||
| DMP357 | PVD AlTiN – basic higher-temperature coating, moderate friction characteristics. | |||
| DMP35-GLH | Premium AlTiN – higher-temperature coating, very low friction characteristics. | |||
| MEDIUM Shock and Wear |
DMK30† | Micro-grain carbide providing higher wear resistance and moderate shock resistance for applications in tough stainless steels, high-temperature alloys, irons and many tool steels. | ANSI C2-C3, ISO K15-K30, M15-M30 | |
| DMK303 | PCD TiCN – low- to medium-temperature applications. | |||
| DMK30-HP | PVD AlCrN – premium low- to medium-temperature coating. Best when coolant is required. | |||
| NEW | DMK30-TCI | Modified AlTiN – premium medium- to high-temperature coating. | ||
| DMK307 | PVD AlTiN – basic higher-temperature coating, moderate friction characteristics. | |||
| DMK30-GLH | Premium AlTiN – higher-temperature coating, very low friction characteristics. | |||
| MEDIUM Shock and Wear |
DMP30 | High wear resistance/moderate shock resistance, recommended for most steel and some ductile iron applications. | ANSI C5-C6, ISO P25-P40 | |
| DMP303 | PCD TiCN – low- to medium-temperature applications. | |||
| DMP30-HP | PVD AlCrN – premium low- to medium-temperature coating. Best when coolant is required. | |||
| NEW | DMP30-TCI | Modified AlTiN – premium medium- to high-temperature coating. | ||
| DMP307 | PVD AlTiN – basic higher-temperature coating, moderate friction characteristics. | |||
| DMP30-GLH | Premium AlTiN – higher-temperature coating, very low friction characteristics. | |||
| HARDEST Wear Resistance |
DMK25 | Highest wear resistance with reduced shock-absorption capabilities. Suitable for all materials where cutting conditions are very stable. First choice for hardened steel (> 52 Rc). | ANSI C2-C3, ISO K15-K25, M15-M25 | |
| DMK253 | PCD TiCN – low- to medium-temperature applications. | |||
| DMK25-HP | PVD AlCrN – premium low- to medium-temperature coating. Best when coolant is required. | |||
| NEW | DMK25-TCI | PVD AlTiN coating. Appropriate for higher-temperature applications such as high-velocity cast iron machining, tough stainless steels, high-temperature alloys and hardened steel. | ||
| DMK257 | PVD AlTiN – basic higher-temperature coating, moderate friction characteristics. | |||
| DMK25-GLH | Premium AlTiN – higher-temperature coating, very low friction characteristics. |
† DMK30 grades are available in XPET only.
| APET Geometry | Traits | XPET Geometry |
|---|---|---|
| Positive/negative cutting edge with T-land | Cutting Edge | Positive cutting edge with a light hone and no T-land |
| Somewhat free-cutting; meant for higher chiploads (>.005" IPT); creates medium burr | Cutting Action | Free-cutting, small burr; can run at lighter chiploads (>.002" IPT) |
| Higher force due to negative edge; will deflect more than XPET | Force | Lower force due to sharper edge; less deflection |
| Higher heat generation than XPET; creates more heat at higher speeds | Heat | Less heat generated due to positive edge |
| Very strong cutting edge; able to withstand more shock and interruptions | Strength | Weaker, due to edge sharpness; not able to withstand significant interruptions |
| Longer edge life due to strong cutting edge; will roll more burr and wear out rather than chip out | Edge Life | Shorter, due to edge sharpness; may chip out if run too long |
| Traits | DMP35 | DMK30 | DMP30 | DMK25 |
|---|---|---|---|---|
| Toughness (Fracture) | Very tough, able to withstand shock and interruptions | Tough and hard; not as tough as DMP35, but tougher than DMK25 | Tough and hard; not as tough as DMP35, but tougher than DMK25 | Not as tough; may fracture in abusive applications |
| Wear Resistance (Edge Life) | Softer carbide, will not last as long as DMK25 | Good - harder than DMP35 but not as hard as DMK25 | Longer life than DMP35, but shorter than DMK25 | Longer edge life due to higher carbide hardness |
| Heat Resistance | Lower heat resistance due to lower hardness of carbide | Good heat resistance - more than DMP35 but less than DMK25 | Higher heat resistance than DMP35, less than DMK25 | Highest heat resistance |
| Resistance to Built-Up Edge | Fair resistance to built-up edge; some buildup may occur – use coolant as a preventative | Good resistance | Poorer resistance to built-up edge; not typically a stainless steel grade | Good resistance |
| Feed Capability | High, due to toughness | Average - less feed than DMP35 but more than DMK25 | Strong feed capabilities, approx. 20% lower than DMP35 | Lower, due to brittleness; run at higher speeds and lower feeds |
| Coolant Capability | Good; toughness gives it more resistance to thermal shock | Good on high temp alloys and some tough stainless steels | Fairly tough; will allow machining with good coolant flow | Not as high; may experience thermal shock unless coolant flow is very good |
| Material | Operating Speed | Geometry | 1st Choice Grade* | Coolant |
|---|---|---|---|---|
| Free machining, low-carbon steels | Low to Medium | XPET | DMP30-HP | Air/Flood |
| Free machining, low-carbon steels | Higher | XPET | DMP30-GLH | Air |
| Medium-carbon steels, tool steels | Low to Medium | APET/XPET** | DMP30-HP / DMK30-HP | Air/Flood |
| Medium-carbon steels, tool steels | Higher | APET/XPET** | DMP30-GLH / DMK30-GLH | Air |
| All steels – interrupted cuts and heavy roughing cuts | All | APET | DMP35-HP / DMP35-GLH | Air |
| Heat-treated steels (48-62 Rc) | Low to Medium | APET | DMK25-GLH | Air |
| Soft stainless steels (303, 304) | Low to Medium | XPET | DMP35-HP / DMK30-HP | Air/Flood |
| Soft stainless steels | Higher | XPET | DMP35-GLH / DMK30-GLH | Air/Flood |
| Tough stainless steels (304L, 316, 400 series and PH series) | Low to Medium | XPET | DMP35-HP / DMK30-HP | Air/Flood |
| Tough stainless steels | Higher | XPET | DMP35-GLH / DMK30-GLH | Air/Flood |
| Cast iron | All | APET | DMK30-HP / DMK25-HP | Air |
| Aluminum alloys, copper alloys | All | XPET-ALU XPET-PCD |
DMK25 / DMK253 | Flood |
| High-temperature alloys, titanium | All | XPET | DMK30-GLH | Flood |
* Only one grade (except for aluminum) suggested. Contact Applications Specialist if first choice doesn't work.
** Customer preference. Both are acceptable – see cutting edge differences above.
Dapra 90° Square Shoulder products are made in the USA.