Jamie Knorring, president of commercial shelving maker B-O-F Corp. in the Chicago area, is planning to buy a used factory machine to make clamps as part of a broader plan to boost worker productivity.

Making workers more efficient isn’t the only factor that makes it a good purchase for him. Buying the equipment can also lower his tax bill.

The new tax law allows firms to claim an immediate 100% deduction when they buy an asset, including purchases of used equipment that have already been written off by previous owners.

“It sweetens the deal,” Mr. Knorring said of the tax benefits of buying the equipment. The company, which has about 70 employees and took in revenue last year of approximately $20 million, is planning to buy other equipment including a welding robot, purchases made easier to justify given the new tax incentive, he said.

Tax planners say the market for used equipment—including railcars, airplanes and industrial machines—is likely to heat up in the months ahead as firms try to take advantage of changes in the tax law. It could mean a shuffling of assets by companies purely for tax reasons and mergers and acquisitions that exploit new tax edges.