Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Tool Bending: A Comparative Study

Seebaiah, Vishnu Simha LU (2026) MMTM05 20261
Production and Materials Engineering
Abstract
This master’s thesis investigates tool bending in solid carbide end mills during shoulder milling of CK45 steel, SS 1.4923, SS 316L, and TiAl6V4. Five different tool designs were tested to evaluate the influence of cutting speed and feed rate on tool deflection, surface quality, and machining stability.

The results show that feed rate has a stronger effect on tool bending than cutting speed. Higher feed rates generally increased deflection and reduced surface quality, while certain tool geometries performed better with lower bending and more stable cutting behaviour. The study demonstrates that both tool design and machining parameters are important for minimizing deflection and improving process reliability in precision milling.
Popular Abstract
When metal parts are made by milling, a rotating cutting tool removes material layer by layer. Ideally, the tool stays in the same and does not bend and follows a perfectly planned path, but in reality, it can bend slightly. This phenomenon is called tool bending, the measured value may seem small, but it can cause noticeable errors in the final part, such as poor surface finish, inaccurate dimensions, extra wear on the tool, or even tool breakage. In industries where precision matters, these effects can lead to higher costs, more scrap, and slower production.

This thesis studied how tool bending varies under different cutting conditions and with different tool designs. Five solid carbide end mills were tested on four materials: a... (More)
When metal parts are made by milling, a rotating cutting tool removes material layer by layer. Ideally, the tool stays in the same and does not bend and follows a perfectly planned path, but in reality, it can bend slightly. This phenomenon is called tool bending, the measured value may seem small, but it can cause noticeable errors in the final part, such as poor surface finish, inaccurate dimensions, extra wear on the tool, or even tool breakage. In industries where precision matters, these effects can lead to higher costs, more scrap, and slower production.

This thesis studied how tool bending varies under different cutting conditions and with different tool designs. Five solid carbide end mills were tested on four materials: a normal steel, a harder stainless steel, a machinable stainless steel, and a difficult titanium alloy. The experiments focused mainly on two most common cutting parameters, cutting speed and feed rate. The goal was to see which one has a stronger effect on bending and to compare how different tools behave under the same conditions.

The main finding was that feed rate had a stronger influence than cutting speed. In simple terms, how much material the tool tries to remove each turn mattered more than how fast the tool was spinning. Some tool designs performed better than others, showing less bending, smoother surfaces, and more stable cutting. One tool even failed early, showing that design differences can strongly affect reliability. The harder materials, especially stainless steel and titanium alloy, were more demanding and generally produced higher loads on the tool.

The study also showed that tool bending is not just a theoretical problem, it is a practical challenge that affects every day manufacturing. By choosing the right tool design and keeping cutting conditions in a safe window, manufacturers can improve accuracy, surface quality, and tool life. In that sense, the work helps turn machining from trial and error into a more predictable and efficient process. (Less)
Please use this url to cite or link to this publication:
author
Seebaiah, Vishnu Simha LU
supervisor
organization
course
MMTM05 20261
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Tool Bending, Solid Carbide End Mills, Tool Deflection.
other publication id
LUTMDN/(TMMV-5387)/1-61/2026
language
English
id
9225468
date added to LUP
2026-04-23 12:32:48
date last changed
2026-04-23 12:32:48
@misc{9225468,
  abstract     = {{This master’s thesis investigates tool bending in solid carbide end mills during shoulder milling of CK45 steel, SS 1.4923, SS 316L, and TiAl6V4. Five different tool designs were tested to evaluate the influence of cutting speed and feed rate on tool deflection, surface quality, and machining stability.

The results show that feed rate has a stronger effect on tool bending than cutting speed. Higher feed rates generally increased deflection and reduced surface quality, while certain tool geometries performed better with lower bending and more stable cutting behaviour. The study demonstrates that both tool design and machining parameters are important for minimizing deflection and improving process reliability in precision milling.}},
  author       = {{Seebaiah, Vishnu Simha}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Tool Bending: A Comparative Study}},
  year         = {{2026}},
}