Realigning Mill Foundations to Eliminate Angular Misalignment

Over the years, Roll-Kraft has conducted thousands of mill evaluations on a variety of equipment. We are now sharing these stories in our Tube & Pipe Field Service Report Article Series. We hope you find the information contained in this series helpful. If you have any questions regarding your mill, use our contact form to request more information about our on-site mill evaluation.

Problem: 
A tube and pipe producer had experienced persistent weld misalignment and profile inconsistencies across several mill runs. Despite good maintenance practices and clean setups, finished product variation continued. Suspecting deeper structural issues, the company requested a full optical alignment and mechanical review of the entire mill bed and forming/sizing sections.

Challenge: 
The investigation revealed that the mill had been aligned in the past using the cut-off die as a fixed point — creating a straight line from the cut-off back to the first breakdown. This historical misalignment distorted the natural centerline of the mill, resulting in shaft misplacement and shoulder irregularities across the breakdown, weld, and sizing passes.

Using custom fixtures keyed to the mill base, Roll-Kraft technicians re-established the true centerline and found multiple offsets. The sizing section was approximately 0.125" to the inboard side, and the cut-off was over 0.250" off center. Several driven shafts required shim adjustment, and one station exhibited loose bearings despite prior replacement.

Additional findings included side pass stations with excessive endplay, SHCS fasteners in need of replacement, and permanent spacers that had not been hardened — leading to shoulder compression and misalignment over time.

Solution: 
The team began by removing the angled reference and establishing a true mill centerline based on the machine bed keyways. Shaft positions were corrected using an optical scope, and shoulder alignment spacers were reground or replaced to match measured values. A custom bar was fabricated to confirm alignment through the weld box, scarf stand, and IP pass.

To improve long-term consistency, Roll-Kraft recommended replacing all “soft” spacers with hardened versions and properly labeling each for repeatability. The sizing section was left offset for now due to coolant system constraints, but provisions were made for future relocation if required.

Fasteners and shims were replaced where needed, and side pass stands were tightened and realigned. With the shoulder and shaft corrections in place, the mill was able to produce straight, round tube with reduced vibration and no additional marking. Final steps included validating the mill’s setup under load using actual tooling and straight edges.

Contact Roll-Kraft for a Tube & Pipe Mill Evaluation
Do you have issues you would like a second opinion on regarding your mill? Roll-Kraft on-site evaluations really make an impression with your staff, confirming you are serious about producing quality tube, pipe, and roll form products. Our technicians will tell you exactly where you are currently doing a great job, in addition to pointing out any areas that could be improved. We have been doing training and evaluations for over 30 years and understand the sensitive nature of bringing someone in to talk about improvements. Your staff will be in good hands with Roll-Kraft. Click here to learn more about our tube & pipe evaluation service.