I am building a project for a robot on breadboard, and I have come across the need for a voltage regulator. I have an existing voltage regulator, but it will not fit into the holes on my breadboard. As a result I have begun to look for a new voltage regulator that will fit into my breadboard. I ran into this voltage regulator with the datasheet here https://www.jameco.com/Jameco/Products/ProdDS/902071.pdf, and in the datasheet it seems to say that the lead width is 0.69 - 0.94. I don't understand why the width of the lead would change and is displayed as a range and which part of the range to count as the lead width. My breadboard only accepts wires between 20-28 AWG. I was wondering if the regulator would fit well into the breadboard without being forced.
The lead widths are merely specified as a range on the datasheet, for various reasons ranging from simple tolerances to manufacturing process changes. Voltage regulators are also notorious for having rectangular (instead of round or square leads) that are wider than breadboard holes will allow.
When I need to use a voltage regulator on a breadboard but it won't insert, I usually solder some small jumper wires onto it similar to how I would use a panel-mount potentiometer:
The leads can then be inserted in the breadboard easily.
However, with a voltage regulator, you need to be careful that it has proper air circulation and/or heatsink.
Why don't you just use the regulator that you have now. Find some short lengths if bare wire that do fit into your breadboard. Then cut three short pieces of this wire and butt solder then along side the regulator leads with the ends sticking out enough so they'll go into the breadboard.
When you add extension wires to a component for use in a breadboard it can be the best idea to lay the part down flat instead of expecting a small number of flexible wires to hold a big part up in the air.
The leads width specification in data sheets shows a range because it is not possible to make the leads all exactly a certain dimension. There will be variation. The vendor specified range covers this tolerance plus a reasonable guard band.
Any regulator in a TO-220 package should have the same lead dimensions. The size range shown is the allowable range of sizes according to the JEDEC standard.
I just tried putting a TO-220 transistor into a plastic breadboard, and it fitted easily - but its leads may be at the small end of the allowable range.
You could solder some #22 or 24 solid wire to the regulator pins, and insert those wires into the breadboard.