Connect A Bike’s Chain With A Chain Tool
Any single-speed or standard derailer chain can be connected with chain tool. Narrow 9, 10 or '11 speed' chains have plates that are too thin to make this a reliable process and connect with special links that are supplied with them. Some chains – for example Shimano - have to be broken and reconnected with a special pin. Others with a trick link that can be dismantled by hand.
Prepare chain tool
Realign both ends of the chain in the slot on the chain tool further from the punch with the holes aligned. The rivet sticking out should be faced toward the punch.
Drive it back through the chain by screwing in the punch on the chain tool. Check how far to push by comparing the back of the link with others. The position of the driven pin needs to match the height of the others.
When the head of the rivet viewed, from the back, matches its fellows, retract the screw and remove the chain from the chain tool. Check the link you’ve just been working on it may be stiff and unable to flex like the others. If it’s stiff it needs to be spread.