The short answer
A used tube mill can be a good buy when its size range covers your products, its condition and electrics check out, and you have a plan for installation, rollers and spare parts. A new tube mill is configured for your product list, material, power supply and workshop, and comes with layout and foundation drawings, commissioning and a technical agreement. If you already run a mill, a third route is often the cheapest: keep the mill and upgrade the entry section, or replace the one machine that limits it.
Whichever route you take, start from the products you want to make, not from the machine that happens to be for sale.
Start from your product list
List every tube you plan to make: outside diameter or side lengths, wall thickness, material and strength, and the standard it must meet. A used mill is only a candidate if its model range covers your largest outside diameter and your heaviest wall together. The method for checking this is in 10 Steps to Specify an ERW Tube Mill: Tube Size to Full Line.
What to check on a used tube mill
- Size range: the original model and the sizes it actually ran. Ask for the maker's specification, not only the seller's description.
- Rollers: which roller sets come with the mill, for which sizes, and how worn they are. Sizes you need that are not included will need new rollers; see Tube Mill Rollers: Roller Sets, Sharing and Size Changes.
- Mechanical condition: stands, shafts, bearings, gearboxes and universal shafts. Look for play, noise, oil leaks and repaired parts.
- Drive and controls: the type of main drive, the age of the drive cabinets and control system, and whether spare parts are still available.
- HF welder: its type, power and age, and whether it suits your largest size and wall. Older vacuum-tube welders and modern solid-state welders differ in efficiency and maintenance.
- Entry and exit equipment: whether the uncoiler, shear & butt welder, accumulator, saw and run-out table are included and suit your coils and cut lengths.
- Electrical match: the supply voltage and frequency the line was built for, compared with your plant.
- Documents: drawings, electrical diagrams, manuals and wear-parts lists. Without them, maintenance and later repairs are much harder.
- See it run: if possible, watch the mill run a size close to yours before it is taken down, and mark the parts as they are dismantled.
Costs that come after the purchase price
The price of a used mill is only part of its cost. Plan for:
- Dismantling, packing, transport and lifting
- New rollers for sizes that are not included, and replacement of worn rollers
- Refurbishment of worn mechanical parts, and of the drive and control system where parts are no longer available
- Rewiring or new drives if the supply voltage or frequency differs from your plant's
- Foundations, cooling water and power supply in your plant
- Installation and commissioning, which take longer without the original maker's drawings and support
- Time: the months before the line produces saleable tube
When a new tube mill makes sense
A new line is usually the better choice when:
- Your product range, material or standard differs from what the available used mills were built for
- You need a particular line speed, accumulator size or saw accuracy
- The line must be built for your local voltage and frequency, electrical brands or standards
- You want layout and foundation drawings issued before delivery, so that foundations are built while the equipment is made
- You want installation, commissioning and operator training by the maker, and acceptance against a technical agreement
InGen MillTek builds new tube mill lines and entry equipment to order. Typical delivery is from about 60 days for single machines and about 120 days for complete lines, subject to contract. When you compare a new line with a used one, compare the same scope; see Comparing tube mill proposals: scope and factory interfaces.
Upgrading the mill you already have
If your mill still makes good tube but the line is slow or stops too often, an upgrade can cost far less than a new line. Typical upgrades are adding a spiral accumulator so the mill keeps running during coil changes, replacing the uncoiler for heavier coils, and moving to a semi-automatic or fully automatic shear & butt welder. These can be added to a mill from another builder once the interfaces are checked: pass line height, line hand, strip width and thickness, and line speed. The full checklist is in Tube Mill Entry Section: Complete Set or Single Machine?
One limit applies: we repair equipment we have supplied, but we do not take on repairs of equipment built by other manufacturers. Without the original specifications and drawings, it is difficult to repair it properly.
Frequently asked questions
Prepared by the InGen Engineering Team. Values are reference values and are confirmed in the technical proposal and technical agreement.
- Is a used tube mill worth buying? It can be, if it covers your sizes, is in good condition, suits your power supply and comes with drawings and rollers you can use. Count the costs after purchase as well as the price.
- What should I check first on a used tube mill? Its size range against your product list, then the rollers, mechanical condition, drives, HF welder, electrics and documents.
- Can you refurbish a used mill from another maker? We do not repair other makers' equipment. We can supply new entry equipment for it after an interface check, or a new line.
- Can you supply rollers for a used mill? Yes, if we built the mill: tell us the mill model and the sizes you need. We do not supply rollers for mills from other builders.
- How long does a new tube mill take? From about 60 days for single machines and about 120 days for complete lines, subject to contract.
- How much does a new tube mill cost? It is configured for your products and plant and quoted for each configuration.
About this article
Prepared by the InGen Engineering Team. This is a general buying guide, not a specification or performance guarantee for any project, and not an assessment of any particular used machine. Final parameters are set in the technical proposal and technical agreement.