Forkardt 3QLCLM, Operating Manual

Page: 27 / 50

Table of contents
3QLCLM
Edition: 04/2014
27
Terms used in the formulas:
Gripping coefficient μsp
Jaw design Material
Material surface at the gripping point
l
a
=
Overhang of the work
piece
a =
Depth of cut
Steel 0.1 0.15 - 1 )
s =
Feed
AI 0.1 0.14 -
K
s
=
Specific cutting force
Ms 0.09 0.14
-
GG 0.08 0.12 -
d
z
=
Machining diameter
Steel 0.12 0.20 0.32
d
sp
=
Gripping diameter
AI 0.11 0.19 0.30
μ
sp
=
Gripping coefficient
Ms 0.11 0.18 0.27
F
s
=
Primary cutting force
GG 0.10 0.16 0.26
Steel 0.25 0.35 0.50
AI 0.24 0.33 0.48
Ms 0.23 0.32 0.45
GG 0.20 0.28 0.40
1) Avoid, smooth jaws are only suitable for gripping machined surfaces
2) Indentations will be produced on the work piece.
The cutting forces increase as the cutting tool becomes dull. An additional factor of safety
S
z
=2
is recommended to allow for all uncertainties in the machining process.
The gripping force must be increased to
allow for the tilting effect caused by the
overhang
.
Specific cutting force Ks (N/mm 2 ) for feed s and
Adjustment angle 70° (Source König, Essel )
Material no. Material Tensile
strength
B
N / mm
2
at
m/min
Feed s (mm)
0.16 0.25 0.40 0.63 1.00 1.60
1.0401 C15G 373 100 2482 2169 1916 1687 1481 1298
The tilting force need not be taken into
account if the work piece is supported by a
tailstock or if the work piece does not
project beyond the jaws by more than 0.5 x
d
sp
. The gripping force F
spz
required can be
found approximately from the formula:
1.0501 C35G 490 100 2577 2237 1927 1668 1441 1241
1.0532 St50-2 559 100 2561 2248 1959 1716 1499 1307
1.0632 St70-2 624 100 2877 2492 2142 1851 1595 1371
1.0711 9S20 371 100 1609 1553 1497 1444 1393 1342
1.1181 Ck35V 622 100 2574 2266 1962 1741 1527 1339
1.1191 Ck45V 765 100 2524 2253 1999 1781 1584 1405
1.1221 Ck60V 673 100 2548 2296 2058 1851 1662 1490
1.3505 100Cr6G 624 100 2904 2551 2239 1968 1726 1510
1.4113 X6CrMo17G 505 100 2378 2107 1854 1638 1445 1272
1.4305 X12CrNiS18.8 638 350 2596 2192 1835 1545 1296 1065
1.5752 14NiCr14BF 658 100 2249 2012 1790 1598 1424 1266
1.5919 15CrNi6 510 100 2271 2051 1842 1661 1494 1342
1.5920 18CrNi8G 578 100 2360 2095 1847 1636 1446 1276
. Tilting factor:
17131 16MnCr5G 510 100 2641 2244 1891 1603 1354 1141
1.7147 20MnCr5G 568 100 2452 2174 1915 1694 1495 1317
1.7225 42CrMo4V 1138 100 2428 2249 2075 1919 1773 1635
1.8515 31CrMo12V 1060 100 2678 2419 2173 1960 1764 1565
1.8519 31CrMoV9V 931 100 2507 2265 2036 1836 1653 1485
3.1354 AlCuMg2 15Hv10 200 953 649 752 66» 593 525
This equation cannot be applied to stepped
work pieces whose gripping diameter is
appreciably smaller than the machining
diameter.
- G-AlMg4SiMn 260 200 829 729 636 558 - -
3.3561.01 G-AlMgS 75HV10 200 886 797 713 641 574 514
0.4020 GG-20 178HB 200 1637 1444 1227 1047 892 757
0.6030 GG-30 206HB 100 1919 1595 1313 108» 899 740
0.7050 GGG 50 194HB 200 1840 1606 1392 1213 1053 913
The feed thrust component F
v
and passive thrust F
p
are not entered in this
formula. They are taken into account with safety factor S
z
!
Simple jaw FNC 50
FNC 51 Stone jaw
Roughing jaw FNC 52