Steel Manager III vs iMetal: Which Jonas-Owned Metals ERP Fits Your Operation?

What Steel Manager III does well

4GL calls itself a trusted provider for over 40 years and describes Steel Manager III as a fully integrated, cloud-based ERP for metal service centers. Users reach it from any device with an internet connection through Chrome or Edge.

Its tools fit cut products. Linear nesting is built in, plate nesting links to SigmaNEST, remnants are tracked, and an Advanced Production Schedule filters by date and raw material. Quoting runs on price books with profitability checks, and both quotes and orders can be imported from Excel. EDI, an eCommerce customer portal, integrated accounting and automatic delivery of mill test reports round it out. Metal Center News reported in February 2026 a typical implementation of three to four months, up to about a year, one of the few published go-live estimates in this market.

Its published testimonials come from shops including Southern Steel Group, Penn Stainless Products, Specialty Metals Corp, McKinnon Metals and ASA Alloys, which runs eight locations in Canada.

What iMetal does well

iMetal is the enterprise product of Jonas Metals Software, a group built from Compusource in California, Metalogic in the UK and PCI Systems. Jonas positions iMetal for complex, multi-site metals operations, including trading, importing, processing and service centres, with Prof.IT as the edition for smaller businesses.

Its clearest published strength is running several sites as one business without taking control away from each. The iMetal page promises real-time inventory visibility across locations, grades and dimensions while sites keep operating locally, consistent pricing and margin rules across the business, full traceability across sites, and quotation and order management. Its processing and conversion control covers slitting, cut-to-length and downstream operations, with visibility of material status, yield and availability.

The customer logos on Jonas Metals' site include Kimco Steel, Curtis Steel, Leengate and Tomrods, and its about page claims more than 4,000 users in more than 10 countries.

What each leaves unsaid

Steel Manager III's product page does not describe slitting, even though flat-rolled products are on its list of specialties. The iMetal page mentions no nesting, EDI or AI, and does not say whether it runs in the cloud or on your own servers; a wider Jonas blog says the group offers both. We found no AI on either product's pages.

Neither describes a planner that decides which open orders go onto which coils across the whole book. Steel Manager III's nesting fits pieces into a bar or plate, and iMetal's processing control shows yield and material status rather than proposing the plan.

How the choice plays out

A Canadian plate and bar house that burns parts to order

Steel Manager III. SigmaNEST plate nesting, built-in linear nesting and a home office in Ontario all point the same way.

A UK stockholder with five depots and a slitting line at one of them

iMetal. Its multi-site model and published slitting and cut-to-length control match that shape of business.

A US flat-rolled processor

Neither makes flat-rolled the center of its published material. Steel Manager III does not describe slitting, and iMetal's slitting control is described for a group that markets mostly to UK and European businesses, though Jonas Metals has a North American office. If either is on your list, ask for a reference running coil at your scale in your region.

Pricing and ownership

Because one owner holds both, ask each sales team how Jonas positions the two products and what the roadmap looks like for the one you are buying.

The bottom line

Plate and long-product service centers in North America or Asia-Pacific should start with Steel Manager III. Multi-site stockholders in the UK and Europe should start with iMetal. If slitting is a large share of your tons, a separate planning tool such as LineSight can work alongside either ERP (how that compares).