Unless you were negligent or working under the table you should not be liable for employer supplied equiptment. You may notify the department of Labor and Industries for improper witholding of your wages.
Good Luck
Please update your post with very specific facts. What type of equipment was it? Did he ask you to use the equipment? Did you use the equipment in a negligent manner, or in a manner that it was not intended for? How much did he agree to pay you? How much did he withhold? What were his threats, specifically? What were his accusations? Why was he upset?
