10 pcs precision angle block set 1 to 5 degree & 5 to 30 degree 10 pcs precision angle block set 1 to 5 degree & 5 to 30 degree 10 pcs angle blocks set accurate angles quickly. Made of high quality hardened steel. Precision ground. 1/4" thickness, 3" length. HARDNESS: HRC56 TO 60 1 degree increments to 5 degree, 5 degree increments to 30 degree. Accuracy +/-0.0001". Any conveivable angles to these increments can be established. Lightly magnetized for better holding. Fitted in deluxe wooden box.