Here's an output from HSMAdvisor of two identical operations, except where the helix angle was changed from 30* to 45*..
Code:
30* HELIX ANGLE
Material: 7075-T6 Aluminum 150 HB
Tool: 0.500in 2FL Carbide Solid End Mill
Speed: 1200.0 SFM/ 9172.0 RPM
Feed: 0.0035 ipt/ 0.0069 ipr/ 63.40 ipm
Chip Thickness: 0.0031 in
Reference Chipload: 0.0035 in
Engagement: DOC=0.875 in WOC=0.137 in
Effective Dia: 0.500 in
Cross Section: 0.4780 x Dia.
Power: 3.8HP
MRR: 7.58 in^3
Torque: 2.17 ft-lb
Max Torque: 7.90 ft-lb
Cutting Force: 104.1 lb
Deflection: 0.0002 in
Max Deflection: 0.0012 in
45* HELIX ANGLE
Material: 7075-T6 Aluminum 150 HB
Tool: 0.500in 2FL Carbide Solid End Mill
Speed: 1200.0 SFM/ 9172.0 RPM
Feed: 0.0038 ipt/ 0.0076 ipr/ 69.96 ipm
Chip Thickness: 0.0034 in
Reference Chipload: 0.0038 in
Engagement: DOC=0.875 in WOC=0.137 in
Effective Dia: 0.500 in
Cross Section: 0.4780 x Dia.
Power: 3.8HP
MRR: 8.36 in^3
Torque: 2.17 ft-lb
Max Torque: 7.90 ft-lb
Cutting Force: 104.1 lb
Deflection: 0.0002 in
Max Deflection: 0.0012 in
Of course it makes a difference, why else are guillotines angled?
Now, its not the biggest difference in the world.. but as it directly relates to pull out force I think its directly relevant.