Page 103 - Carmex - Metric Catalog 2021

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Thread Turning Technical Section

Example No. 3:

Step 1: Choose Thread Turning Method from page A04-5 EX-RH. AMERICAN BUTTRESS
We chose EX-RH Insert & Toolholder. 12 TPI on 40 mm diameter.
Stainless Steel 304
Step 2: Choose Insert from page A01-31: 16 ER 12 ABUT

Step 3: Choose Toolholder from page A02-3: SER 2525 M16

Step 4: Choose Insert Grade from selection on page A04-2
Our choice for Stainless Steel is Grade BMA

Step 5: Choose Thread Turning Speed from chart on page A04-3
We chose 120 m/min. 120 1000 954 RPM
Rotational Speed calculation: 40
Step 6: Choose Number of Threading passes Replacing the standard anvil
with an anvil with negative
from table on page A04-5. We chose 13 passes angle will eliminate side rubbing
Step 7: Find Thread Helix Angle: on page A02-19 for Pitch of 12 TPI and
40 Diameter Helix Angle as shown in the chart is 1º

Step 8: Choose correct Anvil: As can be seen from the chart on
page A04-7, for AMERICAN BUTTRESS Thread, for 12 TPI and 40
Diameter a negative anvil AE16-1.5 should replace the standard
anvil supplied with the toolholder Anvil chosen:
AE16-1.5
Troubleshooting

Chipping Crater Wear Build-up Edge

1. Use a tougher carbide grade 1. Reduce cutting speed 1. Increase cutting speed
2. Eliminate tool overhang 2. Apply coolant fluid 2. Use a tougher carbide grade
3. Check if insert is correctly 3. Use a harder carbide grade
clamped
4. Eliminate vibration
Thermal Cracking Deformation Fracture

1. Reduce cutting speed 1. Use a harder carbide grade 1. Use a tougher carbide grade
2. Apply coolant fluid 2. Reduce cutting speed 2. Reduce depth of cut
3. Use a tougher carbide grade 3. Reduce depth of cut 3. Index insert sooner
4. Apply coolant fluid 4. Check machine and tool stability

A04-9