Page 892 - Tungaloy Catalog

Regrinding Procedures

Regrinding method [Applied to DSX, DSC, DSC-F, DSC-FQ, DSE, DMX, DMX-F, DMX-FQ and DSS]
Before regrinding
Check the cutting edge for damage and wear. If any large fracture is found, remove with a silicon carbide wheel.
(1) Grinding the flank
d Use a 280 to 400 grit diamond cup type wheel of 100 ~ 200 mm in
diameter.
1) Grind the relief surface so that primary relief angle (θ) of 2° can be formed
as shown in Fig.1. After grinding the other side likewise, do sparkout Fig. 1 Grinding relief angle
grinding so that the difference of the lip height will be kept within
0.02 mm. DSX, DSE and DSC type for steels
2) In the cases of DSX,DSE and DSC type for steels: Turn the drill by Primary θ4 Secondary
θ4° and secure it there. Then grind secondary relief surface so that relief relief
secondary relief angle (θ) of 3° can be formed whie taking care to bring
the ridge line formed between the primary and secondary relief surfaces θ1 Point angle
to the drill center. (Values (θ) of 1° ~ 4° are shown in Table1.)
3) In the cases of DMX, DMX-F, DMX-FQ, DSC-F, DSC-FQ and DSS types: C
After grinding the primary relief angle (θ) 2°, without rotating the drill, A
B
grind the secondary relief surface so that the relief angle (θ) of 3° can be Using points A and B as
formed. In the same way as 2), take care to bring the ridge line formed reference, obtain level.
between the primary and secondary relief surfaces to the drill center. θ2 Primary relief
DSC-F, DSS, and other types angle
Table1. for cast irons and aluminum alloys Viewed from C.
θ 1 θ 2 θ 3 θ 4 Primary Secondary
relief
relief
(Point angle) (Primary relief angle) (Secondary relief angle) (Rotating angle)
DSX, DSE –20° –7° ~ 10° 5°

DSC 12°
DMX –– θ3 Secondary

DMX–F –25° –10° ~ –12° –24° ~ –26° –– relief angle

DMX–FQ ––
DSC–FQ –– Ridge line formed between Viewed from C.
primary and secondary relief
DSS –20° –– surfaces
DSC–F –25° –2° ––
(2) Thinning
• Use a 280 ~ 400 grit diamond straight-type wheel of 100 ~ 200 mm in diameter.
(For thinning of DMX and DMX-F types, consult us separately.)
• Conduct thinning in the same manner as cross thinning (X-type). Fig.2-a DSC type for steels
• For DSC type drills, take care to leave the part of secondary relief by 0.05
to 0.1 mm as shown in Fig. 2-a and Fig. 2-b.
• For DSC-F and DSS type drills, do not leave those parts as shown in Fig. 2-b.
• Values of β1 to β3 written in the figures are given in the Table 2.
11 Table2. β1 β2
β 1 β 2 β 3 R
DSX, DSE (Fig. 2–b) 140° ~ 145° 38° ~ 42° 108° ~ 112° –– β3
Drilling Tools DSC–F (Fig. 2–b) 132° ~ 138° 38° ~ 42° 108° ~ 112° –– 0.05 ~ 0.1
DSC
40° ~ 50° 100° ~ 105° ––
(Fig. 2–a)
150° ~ 156°
DSS
(Fig. 2–b)
(Fig. 2–b)
DMX

DMX–F
(Fig. 2–b)

DMX–FQ
DSC–FQ (Fig. 2–b) 132° ~ 138° 38° ~ 42° 123° ~ 127° R1~5
(Fig. 2–b)
Fig.2-b DSX, DSE, DSC-F, DSC-FQ, DMX, DMX-F, DMX-FQ and DSS types
β2
β1
0
β3
R
β3
DSX, DSE, DSC-F, DSS DMX, DMX-F, DSC-FQ,
DSX, DSE, DSC-F, DSC-FQ, DMX, DMX-FQ
DMX-F, DMX-FQ, DSS

11–76