In determining the size of the steel for the order. Buyers need to take into account
the size lathe with a practical use.
Because in the steel manufacturing process. Steel goes through several processing steps.
The process involves Thermal processes, such as rods, hot rolled annealing or hardening
and bake a night, depending on size.
And distribution of steel grade. As a result, steel A defect in the surface. The loss of
Carbon surface (Decarburization) which resulted in the carbon steel surface within less.


When the steel to be hardening. As a result, the hardness is not required. In addition to
cracking and potential.The steel surface May have small cracks. The rods or rolled.
There are also other types of surface defects. It has a distinct lack of control in the face of
this degree. By the standards of Germany has set the standard DIN 17350 The allowance
for machining of steel. The iron and peeling skin. Available in

Figure 1 and Table 1, which is the smallest size available for machining (Machining Allowance),
the buyer should steel them for size. Before cutting lathe


Table 1 shows the minimum sizes for lathe (Machining Allowance) according to DIN 17350, part 10.
Tolerances


ขนาดเส้นผ่านศูนย์กลาง
หรือความหนา (d)
หน่วย มม.
d  16
16 < d  25
25 < d  40
40 < d  63
63 < d  80
80 < d  100
100 < d  125
125 < d  160
160 < d  200
200 < d  250
250 < d  315
315 < d  400
400 < d  500
500 < d  600
d > 600
เหล็กกล้าเครื่องจักรกล
(Rolled or as-forged steel)
เหล็กกล้าเครื่องมือ
(Peeled or turned steel)
ขนาดเผื่อกลึงน้อยที่สุด
(Machining Allowance)
หน่วย มม.
พิกัดความเผื่อ
(Tolerance)
หน่วย มม.
ขนาดเผื่อกลึงน้อยที่สุด
(Machining Allowance)
หน่วย มม.

+1 - 0 + 0.4 +0.5
+2 - 0 + 0.4 +0.5
+3 - 0 + 0.6 +0.8
+4 - 0 + 0.6 +0.8
+5 - 0 + 0.6 +1.0
+5 - 0 + 0.6 +1.5
+6 - 0 + 1.0 +1.5
+8 - 0 + 1.0 +1.5
+8 - 0 + 1.0 +2.0
+10 - 0 + 1.0 +2.0
+10 - 0 + 1.0 +2.5
+15 - 0 + 1.6 +3.0
+15 - 0 + 1.6 +3.0
+15 - 0 + 1.6 +3.0
+25 - 0 + 1.6 +3.0