Summary

A shredding shaft is the main shaft of a shredder. It carries high torque and repeated impact loads throughout operation. When a plant must import this part, local manufacturing reduces its dependence on overseas suppliers. This article first explains shredder shaft principles and how engineers recreate replacement parts based on technical sources. It then presents a job by MTE (Machinery Technology and Engineering) as a WCE case study.

1. What Does a Shredding Shaft Do?

A twin-shaft shredder uses two counter-rotating shafts. Each shaft carries several cutting tools that work like scissors to grip and cut the feed material. These machines run slowly with high torque. For example, one manufacturer lists maximum speeds of about 11–18 rpm for its standard models. These models handle materials such as cables, small appliances, and scrap tires [1].

2. Key Principles

2.1 A Heavily Loaded Shaft

Machine design texts explain that shaft design must account for several factors. These include combined bending and torsional stresses, fatigue under repeated loading, and stress concentrations at shoulders and keyways. In addition, designers must limit deflection, because it affects bearings and mounted components [2]. A shredder shaft carries these loads continuously. Therefore, the workshop must machine it accurately to the dimensions and tolerances on the drawing.

2.2 Creating Drawings from an Existing Part

Sometimes the original drawings are not available. In that case, reverse engineering recovers information from an existing part to produce a new design. A study in MATEC Web of Conferences describes four stages. First, engineers capture the geometry of the original part. Next, they build a 3D model. Then, they simulate manufacturing by computer. Finally, they produce the part on CNC machine tools [3].

2.3 Why Replace Imported Parts Locally

A supply chain case study looked at adding qualified alternative suppliers alongside the original equipment manufacturer (OEM). It found three benefits: cost savings, shorter delivery times, and localization. These benefits matter most when OEM parts become obsolete or hard to source [4].

3. Case Study: Shredding Shaft Manufacturing by MTE

• Scope: Design and manufacture of a new shredding shaft (position 2 of the machine) to replace an imported part
• Client: Steel recycling operator
• Duration: 20 April – 18 August 2026 (about 4 months)
• Progress: Plan 100% / Actual 100%

The cover image shows the work in stages. The large image on the left shows the completed rotor assembly. On the right, from top to bottom, the small images show milling of a disc-shaped component, turning of the shaft, and the rotor on a lathe. We edited all images with AI so that no individuals or clients can be identified.

4. Observations

• Large imported machine parts can keep equipment idle longer than necessary.
• In this job, the MTE team handled both design and machining locally. As a result, the team completed the part fully on plan.
• For this reason, local manufacturing offers one option for plants that want to reduce spare-parts risk.

5. WCE Services

MTE (Machinery Technology and Engineering) provides design, manufacturing, and repair of machine components for industrial plants.

To discuss your project: +66 65-937-6283 | international@wce.co.th | www.wce.co.th
We engineer your success.

References

(Accessed 2 Oct 2026)
[1] BHS-Sonthofen GmbH (March 2023). Rotary Shear (VR)—Robust and versatile heavy-duty twin-shaft shredder (manufacturer product literature). BHS-Sonthofen product flyer (PDF)
[2] Budynas, R. G. & Nisbett, J. K. (2019). Shigley’s Mechanical Engineering Design (11th ed.). McGraw-Hill. ISBN 978-0-07-339821-1 (chapter on shafts and shaft components)
[3] Stănăşel, I., Blaga, F., Buidoş, T. & Crăciun, D. (2018). Reverse engineering and the CAD-CAM approach for the manufacturing of spare parts. Case study. MATEC Web of Conferences, 184, 03004. https://doi.org/10.1051/matecconf/201818403004
[4] Al-Theeb, N. A. (2023). The impact of procuring reverse-engineered spare parts on the supply chain: A case study. Journal of Supply Chain Management, Logistics and Procurement, 5(4). https://hstalks.com/article/7761/