Page 212 - JBO-Katalog-2022

M MF UNC UNF

M Technical Information
MF
MJ
EG M

G
Rc, R
Pg

UNC
UNF
UN
UNJF

NPT Rollable materials
NPTF thread P blank dia. thread P blank dia.
[mm] [mm] [Gg/1“] [mm] JBO thread rolling dies are suitable for cold formable
materials with a minimum elongation of approx. 8 %
2
guide val. tol. 6g guide val.tol. 2A and up to approx. 900 N/mm tensile strength.
≤ M 1,4 tol. 6h
Workpiece preparation
M 1 0,25 0,80 UNC Nr. 1 64 1,55 The workpiece to be rolled must be prepared to the
M 1,2 0,25 1,00 UNC Nr. 2 56 1,84
blank diameter. This coresponds to the standard value
M 1,4 0,3 1,16 UNC Nr. 3 48 2,10 due to the difference in the materials that can be
M 1,6 0,35 1,31 UNC Nr. 4 40 2,36 rolled and, if necessary, is increased in steps of 0.01
M 1,7 0,35 1,42 UNC Nr. 5 40 2,69 mm until the thread profile is almost fully formed.
M 1,8 0,35 1,52 UNC Nr. 6 32 2,91 A further increase in diameter would damage the tool
M 2 0,4 1,67 UNC Nr. 8 32 3,57 due to overloading. Please observe the thread major
M 2,2 0,45 1,84 UNC Nr. 10 24 4,05 diameter tolerances (see pages 158 and 160).
The workpiece must have a 15–20° chamfer so that
M 2,3 0,4 1,98
M the rolling die rolls on easily.
MF M 2,5 0,45 2,13 UNF Nr. 0 80 1,27 Both chamfer and blank diameter must run con centrically.
M keg.
M taper M 2,6 0,45 2,25 UNF Nr. 1 72 1,58 The transition between the blank diameter and any
M 3 0,5 2,60 UNF Nr. 2 64 1,87 undercut at the end of the thread should be at an
G angle a of approx. 30°. A 90° undercut causes chipping
BSW M 3,5 0,6 3,03 UNF Nr. 3 56 2,15
BSF of the thread rolls and must therefore be machined
DIN 477 M 4 0,7 3,46 UNF Nr. 4 48 2,43
R, BA, Pg after thread rolling.
M 4,5 0,75 3,93 UNF Nr. 5 44 2,73
UNC M 5 0,8 4,39 UNF Nr. 6 40 3,02 Rolling speed
UNF 1 5,25 36 3,63 We recommend thread rolling speeds ranging from 20
UNEF M 6 UNF Nr. 8
UN, UNS M 7 1 6,25 UNF Nr. 10 32 4,23 to 50 m/min. The top speeds are suitable for brass and
M 8 1,25 7,08 bronze and medium speeds for free-cutting steels.
NPSM The lower speeds have to be used for steels that are
NPT difficult to form. Adequate lubrication with cutting oil
NPTF
Tr, Rd M 2,5 0,35 2,22 is necessary.
M 3 0,35 2,72
M 3,5 0,35 3,22 JBO thread rolling dies have thread rolls with lead profile
A more accurate thread profile and a more accurate
M 4 0,35 3,72 pitch are thereby achieved. With materials that are
M 4 0,5 3,60 difficult to form, the lead profile also extends the life
M 5 0,5 4,60 of the thread rolls.
M 6 0,5 5,60
M 7 0,5 6,60
M 8 0,5 7,60 Setting instructions
M M 6 0,75 5,43 adjustable thread rolling dies RSV by means of thread rolling die holder RSV 2 to 10.
MF 1. Place the rolling die on the die holder, screw on the nut until it is centred and lightly in
M 7 0,75 6,43 contact. Lock with locknut.
M 8 0,75 7,43 2. Turn workpiece outer diameter to guide value of the blank diameter, roll thread, check
G M 8 1 7,25
BSW effective diameter.
BSF M 10 1 9,25 3. To correct the thread dimensions, first adjust the effective diameter with the nut. Then
R, Pg
MF-EL correct the thread maximum dia meter by altering the blank diameter in accordance with
the procedure described in ”Workpiece preparation”.
UNC, UNF
UNEF
UN, UNS
UNJC
UNJF
NPT 212
NPTF
Tr
EG