26mm x 150mm
Video-Understanding cold chisels: https://youtu.be/e7umWmyjkGI
Article-Using a cold chisel: https://www.popularmechanics.com/home/how-to/a10915/diy-skill-of-the-day-using-a-cold-chisel-17021541/
Article-Types of Chisels: https://www.homestratosphere.com/types-of-chisels/