Key for Jagstang bridge

Hi!

I've got a problem with my bridge, none of metrics nor english allen keys fit. What do you use to adjust your Jagstang bridge?

Do you use a hammer?

I just bought one of those multi-allen-key tools from the hardware store, Metric for Jag-Stang because it's Japanese.

I always use hammer to fit any thing like this.

A hex head 1.5 works on my bridges.