Advantages and Disadvantages of Using a 45-degree Face Mill vs.
a 90-degree Face Mill

To achieve greater productivity and problem-free milling, use a lead angle cutter whenever possible. Chip thickness is affected by the lead angle. The greater the lead angle, the greater the chip-thinning effect.

Example:

Lead Angle                 Feed per Tooth                Actual Chip Thickness

0                                         A                                                 A

45                                       A                                            .707 x A

0                                      .010"                                              .010"

45                                    .010"                                 .707 x .010" = .0071"

• Well-balanced axial and radial cutting forces.
• Less breakout on workpiece corner.
• Entry shock is minimized.
• Less radial forces directed into the spindle bearings.
• Higher feed rates possible.
• Reduces chatter.

Disadvantages

• Reduced maximum depth of cut due to lead angle.
• Larger body diameter can cause fixture clearance problems.
• No 90-degree corner milling.
• Can cause chipping or burring on exit side of cutter rotation.

Technical Tip #124 - 45-Degree vs 90-Degree Face Mills

                      (1)    (2)   (3)   (4)   (5)   (6)   (7)   (8)   (9)   (10)  (11)  (12)  (13)

ANSI  Inch     S       E     K     R     4      2     AF    T     N      6      G      D     P 
 

1. First station indicates shape of insert.
2. Second station shows relief angle or rake angle of the insert.
3. The third station provides a working gage for repeatability. It sets tolerance to the I.C. (inscribed circle) and creates a gage tolerance for the I.C. to the over-the-nose radius along with the thickness of the insert.
4. Fourth station indicates geometry and clamping insert type. It designates with or without hole, shape and size of hole, chipbreaker form, and single- or double-sided insert.
5. Fifth station indicates I.C. size of the insert.
6. Sixth station designates insert thickness.
   i. T = 1/16" inch increments
7. Seventh station designates corner configuration of the insert.
8. Cutting edge form
   i. F for sharp
   ii. E For Honed edge
   iii. T for T-Land
   iv. S for Honed T-Land
9. Designates N for neutral, R for right-handed, or L for left-handed insert
10. Designates facet width of insert
    i. 2 - .0312"
    ii. 3 - .0469"
    iii. 4 - .0625"
    iv. 6 - .0938"
11. Edge prep size
    i. L – Light sharp or lightly honed or T-landed
    ii. G – General Medium hone and/or  T-land
    iii. H – Heavy – large hone and/or T-land
12. Rake face angle
    i. Angle on insert prior to installation.
    ii. N – 0 degree, A – 3 degree, B – 5 degree, C – 7 degree, P – 11 degree,
    iii. D- 15 degree, E – 20 degree, F - 25 degree, G – 30 degree.
13. Added Information
    i. J – polished rake face
    ii. P – partial T-land
    iii. W – Wiper Insert

Technical Tip #127 - Understanding Milling Insert Identification

There are several different ways to machine a slot using the Z-axis plunge mill.

Download the pdf to read the complete technical tip and see the accompanying illustrations.

Technical Tip #132 - Slotting with a Z-Axis Plunge Mill

When an indexable milling cutter is used and the radial engagement is less than 50% of the cutter diameter, the feed rate must be adjusted to compensate for chip thinning.

To read the complete technical tip and see the accompanying illustrations, download the pdf.

Technical Tip #144 - Feed Rates in Reduced Cutting Diameter