Общий каталог Tungaloy 2020 - 2021 - страница 1658

Regrinding method [ A p p l i e d to D S W ]

Please refer to the following instructions prior to regrinding DSW type drills. 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 fl ank

Fig. 1 Grinding relief angle Use a 280 to 400 grit diamond cup type wheel of 100 ~ 200 Point angle mm in diameter. θ1° 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 C side likewise, do sparkout grinding so that the diff erence of the lip height will be kept within

2) In the cases of DSW types: After grinding the primary relief Viewed from C. angle (θ) 2°, without rotating the drill, grind the secondary relief surface so that the relief angle (θ) of 3° can be formed. In the same way as 2), take care to bring the ridge line A

formed between the primary and secondary relief surfaces B Secondary

(2) Thinning θ1 θ2 θ3

Use a 280 ~ 400 grit diamond straight-type wheel of 100 ~ 200 Table 1 (Primary relief (Secondary relief

mm in diameter. (Point angle) angle) angle)

Conduct thinning in the same manner as cross thinning (X-type). DSW –20° –6° ~ –12° –23° ~ –27°

• Values of β1 to β3 written in the fi gures are given in the Table 2.

Table 2 β1 β2 β3

DSW 147° ~ 153° 30° ~ 42° 95° ~ 110°

Fig. 2

β1 0

β2

β3

(3) Honing

• The honing angle θ and width H should be varied depending on the

drill type, diameter, and work material. Recommended honing specifi cations are given in the Table below.

• Honing procedures (refer to Fig.3)

(1) Round the R portion shown in Fig.3 in large. (2) Then, roughly hone the cutting edge lines by using an electro-deposited diamond fi le of around 170 grit. (3) Carry out fi nish honing by using a diamond hand stick of 400 to 600 grit.

• The honing width should be changed depending on the drill diameter. For smaller side of diameters, the width should be in smaller side of values given in the Table.
• Angle honing

~ ø6 mm ø6 ~ ø10 mm ø10 ~ ø16 mm

θ - 20º - 20º - 20º

H 0.03 ~ 0.05 0.05 ~ 0.08 0.08 ~ 0.1

• R Honing

Fig.3

Angle face Rake face

After regrinding, check the following before use. （A-A section） （A-A section）

Notes:

• The diff erence of the lip height is kept within 0.02 mm.
• For more details on regrinding, consult the nearest Tungaloy sales offi ce.
• Any damaged portion on the cutting edges is not left.
• Cutting edges are properly honed.
• Any grinding burr is not left.