Technical Information
Finish Boring Speeds
Effects of Finish Feed Rates
The best surface finish is produced when the tool is fed at approximately 25% of the tool nose radius. The effect on chip formation of the feed rate and depth of cut is illustrated below:
Depth of Cut
The depth of cut must be sufficient to allow the tool to cut and not rub. Too small a cut will cause the tool to be pushed away from the workpiece by the cutting pressure. The depth of cut must be large enough to let the insert bite as it cuts. Depth of cut is a function of material and insert nose radius. Generally, the ideal minimum diametral depth of cut is equal to the insert nose radius.
A larger nose radius produces a better surface finish. Care must be taken not to over feed the nose radius.
| Variable | Low Speed | High Speed |
|---|---|---|
| Machining Time | Longer | Shorter |
| Surface Finish | Coarser | Finer |
| Probability of Vibration | Lower | Higher |
| Material | BHN | TR / TT / SN | C1 / C2 | AL | AS | TE |
|---|---|---|---|---|---|---|
| Carbon Steel C = 0.15% | 125 | 550-750 | 600-800 | 150-350 | 650-1000 | 950-1300 |
| Carbon Steel C = 0.35% | 150 | 525-800 | 600-800 | 150-350 | 625-950 | 850-1200 |
| Carbon Steel C = 0.70% | 180-250 | 425-625 | 550-750 | 150-250 | 500-750 | 750-950 |
| Alloy Steel 4000 | 125-200 | 425-625 | 550-750 | 150-250 | 500-750 | 750-950 |
| Alloy Steel 5000 | 225 | 250-500 | 350-525 | 150-250 | 300-600 | 400-650 |
| Alloy Steel 8000 | 300 | 200-400 | 300-525 | 100-200 | 350-475 | 400-500 |
| Stainless Steel, Annealed 400 SERIES | 150-270 | 400-625 | 400-600 | 150-250 | 475-750 | 425-650 |
| Stainless Steel, Annealed 300 SERIES | 150-220 | 450-550 | 350-500 | 150-300 | 550-650 | 425-650 |
| Cast Steel, Low Carbon | 150 | 325-450 | 450-650 | 100-250 | 400-550 | 475-600 |
| Cast Steel, Low Alloy | 150-250 | 250-350 | 250-400 | 100-250 | 300-425 | 400-575 |
| Cast Steel, High Alloy | 160-250 | – | 250-400 | 75-250 | – | 400-500 |
| All values are in SFM. | ||||||
| Material | BHN | TR / TT / SN | C1 / C2 | AL | AS | TE |
|---|---|---|---|---|---|---|
| Malleable Cast Iron, Ferritic | 110-150 | 525-700 | 300-450 | 600-1100 | 700-1000 | – |
| Malleable Cast Iron, Pearlitic | 150-270 | 250-400 | 200-250 | 600-1000 | 300-750 | – |
| Grey Cast Iron, Low Tensile | 150-220 | 525-800 | 325-525 | 400-1200 | 600-1600 | – |
| Grey Cast Iron, High Tensile | 200-330 | 350-600 | 225-400 | 400-900 | 350-900 | – |
| Nodular Iron, Ferritic | 125-230 | 300-500 | 300-400 | 400-950 | 450-900 | – |
| Nodular Iron, Pearlitic | 200-300 | 250-400 | 200-350 | 400-700 | 350-700 | – |
| Aluminum Alloys | 30-120 | – | 600-3000 | – | – | – |
| Aluminum Alloys,Cast | 100-130 | – | 600-3000 | – | – | – |
| Extra Hard Steel | 50-65RC | – | 60-120 | – | – | – |
| Waspalloy, Discalloy, Incoloy | 180-250 | – | 50-200 | – | – | 150-350 |
| Monel, Inconel | 125-250 | – | 45-90 | – | – | 90-300 |
| Titanium | 100-200 | – | 120-250 | – | – | 325-500 |
| Copper, Brass, Zinc | 50-150 | – | 500-1000 | – | – | 50-1500 |
| All values are in SFM | ||||||
