S.K. Machine Tools Private Ltd. was founded in 1986 as an ancillary to Praga Tools Limited, Hyderabad. In its initial years, the company manufactured machine tool accessories and precision components for Praga Tools, antenna gear box assemblies for the Electronics Corporation of India, and other "SPM fixtures" for the "HCL" and Voith India Private Limited. In 1994, S.K. Machine Tools built a second unit with high-precision machines to build "small arm components" and "precision components" for the Bharat Dynamics Limited, ordnance factories, and other companies.

S.K. Machine Tools Private Limited manufactures:

• Air charging units that facilitate charging and discharging of the air bottle used in the electro-pneumatic actuation systems of the Akash and Trishul surface-to-air missiles.
• On-off solenoid valve used in the electro-pneumatic actuation systems of the Akash and Trishul missiles

Sources:
[1] S.K.M. Tools Private Limited, www.skmtools.com;
[2] Dr. N.C. Birla and B.S. Murthy, eds., "Control and Guidance," Indian Defence Technology: Missile Systems (1998: DRDO, Ministry of Defence, New Delhi), pp. 136-137, 141-142.