Hyd-Mech H28A-120, Руководство по обслуживанию и запасным частям

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2.15
STEP 4: DETERMINE OPTIMUM BLADE SPEED, V (ft/min) (m/min)
The relationship between optimum blade speed and effective material width for various materials is represented on the
graph shown.
The graph shows that as effective material width gets wider or as material gets harder, lower blade speeds are recom
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mended. If material is narrow or soft, higher blades speeds should be selected.
Example #1
1. 8” (200mm) diameter #1045 Medium Carbon Steel solid bar is to be cut.
2. On the graph above find the Medium Carbon Steel Curve which represents the optimum blade speeds for 1045
Carbon Steel.
3. On the horizontal axis (effective material width axis) find number 8 which represents effective material width of an
8” (200mm) diameter solid.
4. Find the point where a vertical line from 8” (200mm) intersects the Medium Carbon Steel Curve.
5. From this intersection point run horizontally left to the vertical axis (optimum blade speed axis) and find the point
marked “200”.
6. For 8” (200mm) diameter, 1045 Carbon Steel solid bar 200 ft/min (60m/min) is the optimum blade speed.
NOTE:
1. Higher than optimum blade speed will cause rapid blade dulling. Lower than optimum blade speeds reduce
cutting rates proportionately and do not result in significantly longer blade life except where there is a vibration
problem. If the blade vibrates appreciably at optimum speed as most often occurs with structurals and bundles, a
lower blade speed may reduce vibration and prevent premature blade failure.
2. Material Hardness - The graph above illustrates blade speed curves for materials of hardness 20 RC (225 Bhn) or
lower. If the material is hardened then the multipliers need to be used. These multipliers are given in the NOTE at
the bottom right of the graph. As the hardness increases the optimum blade speed decreases.