1/4"-20 x 1" Thumb Screw Stainless Steel - Black Knurled Round Plastic Knob - Standard/Coarse Thread Thumbscrew - Length: 1.000" - Proudly Built in USA - Package of (4): Amazon.com: Industrial & Scientific
Plastic Round Head Thumb Screw | #8-32 x 5/8 Screw Length
M6x45mm Thread Carbon Steel Knurled Round Head Thumb Screws Silver Blue 5pcs - Walmart.com
Computer PC Case Round Head Knurled Thumb Screws Royal Blue 6#-32 4pcs - Walmart.com
5pcs/lot m3 m4 m5 m6 knurled Nylon Round Plastic Head Handle Thumb Screw Bakelite Bolt Black Bakelite hand screw - SINONING- Electronics DIY Accessories Store
Round Knurled Plastic Head Screw - For Better Leverage
Source Carbon Steel White Galvanized Regular Round Head Thumb Screw Type A on m.alibaba.com