Obeng ketok

Obeng ketok atau Impact driver adalah alat yang digunakan untuk mengencangkan atau melepas sekrup dengan kekencangan yang lebih. Diaplikasikan dengan cara metutar gagang obeng kearah mengencangkan atau mengendorkan kemudian menahan dengan tetap menekan, selanjutnya ujung gagang obeng dipukul dengan palu.

Mata obeng dapat diganti-ganti sesuai ukuran yang pas dengan kepala sekrup.

Referensi 

 Mayer, Paul. "Impact Driver - Do I really need an Impact Driver?". Woodworkers Guild Of America. Retrieved 2015-09-21.
 "Canadian Inventions – The Robertson Screwdriver System (Peter Robertson)". "Millions of craft workers are thankful to Canadian Peter Robertson for inventing the square-head screw that bears his name. The Robertson screw represented a significant advance in the history of fasteners for two practical reasons: it is self-centering (that is, the screw is almost impossible to be driven off-centre because of the indented squared notch into which the screwdriver fits snugly) and the screw can be driven with only one hand."

Alat tangan