M3/M4/M5/M6/M8 Carbon Steel Black Zinc High-Step Head Hand/Finger Tighten Thumb Screw - China Knurled Thumb Screw, Hand/Finger Turning Screw | Made-in-China.com
PrecisionGeek - KNURLED SHOULDER THUMB SCREWS Aluminium BLACK M5 x 10mm (10mm dia) HAND GRIP BOLTS (Set of 4)