Why does India still import its ball screws and linear guideways?

In FY2022-23 India imported machine tools worth ₹13,671 crore — more than the ₹12,328 crore it produced at home. The components that give those machines their accuracy, ball screws and linear guideways, come overwhelmingly from abroad.

These parts are the muscles and rails of a CNC machine tool. A ball screw converts a motor's rotation into precise linear travel; a linear guideway carries the moving axis along a hardened rail. Together they set how accurately a machine can position a cutting tool. Getting there means grinding hardened steel shafts to sub-micron lead accuracy, hardening raceways without warping long, slender screws, and certifying the result against accuracy grades from C0 to C7. Few nations do this at scale — Japan, Taiwan, Germany and South Korea dominate the market.

India has one genuine indigenous maker. MTAR Technologies manufactures high-precision ball screws up to 7 metres long, 8 to 100 mm in diameter, in accuracy classes from C1 to C7, and supplies them to nuclear power stations, BARC, aerospace, defence and machine-tool customers. It is a demonstrated capability, but a niche one — limited-production output for critical applications, not a scaled commercial industry.

The commercial CNC market runs elsewhere. Global makers such as THK service Indian buyers directly through India-facing operations, while small workshops advertise ground ball screws on B2B marketplaces at grades and volumes that are not independently established. The Indian Machine Tool Manufacturers' Association calls machine tools the "mother machines" of manufacturing — they make other machines possible. Their precision components remain imported, and the dependence is deepening: imports were about 56% of India's ₹24,536 crore machine-tool consumption in FY2022-23, up from roughly 50% two years earlier.

The gap persists because the foundations beneath a ball screw are themselves still emerging in India. Precision thread and raceway grinding, bearing-grade alloy steel, precision metrology to certify accuracy classes, superfinishing, and the encoders that close the feedback loop — each is a hard capability in its own right, and each is only partly in place. A ball-screw industry is the sum of these, not a single product line.

What it would take is the assembly of that stack. IMTMA's own guidance calls for government-encouraged local production of high-precision components to cut import dependence and costs. The institutional scaffolding is forming — the AMTDC R&D centre with IIT Madras and the Department of Heavy Industry, the AMTTF testing facility with DPIIT, and a May 2025 IMTMA–IIT Madras research agreement. The direction is set; the depth is what remains to be built.