Blasting cap and Detonating device

Blasting cap noun - A small tube filled with detonating substances; used to detonate high explosives.

Detonating device and blasting cap are semantically related. In some cases you can use "Detonating device" instead a noun phrase "Blasting cap".

Detonating device noun - A mechanical or electrical explosive device or a small amount of explosive; can be used to initiate the reaction of a disrupting explosive.

Blasting cap and detonating device are semantically related. Sometimes you can replace phrase "Blasting cap" with "Detonating device", this phrases are similar.