Oct 26, 2026Buying Guides
Flat Screwdriver Sizes: From Terminal Screws to Door Hinges
3x75 to 6x200 mm - which flat blade sizes cover which jobs, how the two numbers read, and the sizes a starter range actually needs.
How a flat screwdriver size reads
A flat screwdriver size is two numbers: blade width x length in millimetres. A 5x100 blade is 5 mm wide and 100 mm long from tip to handle. Width must match the screw slot - too narrow and the blade cams out, too wide and it will not enter the slot at all. Length is reach: longer blades reach recessed screws; shorter blades sit closer to the hand and transmit torque more directly.
The working range, job by job
3 mm blades (3x75, 3x100) are terminal and electronics screws. 5 mm blades (5x75 to 5x150) cover switch plates, sockets and most household screw work - the 5x100 is the everyday size. 6 mm blades (6x100 to 6x200) take door hinges, furniture assembly and tougher fixtures. The catalog's S2 range runs 3x75 through 6x200 in ten steps, so one series spans the jobs from the smallest terminal screw up to door-hinge hardware.
The two problem-solver models
Two special bodies sit outside the flat range. Telescopic models (H4.0x25-75 and H6.35x75-150) extend to reach recessed screws, and a dual-purpose H6.35x100 takes both flat and Phillips work. They answer jobs a standard blade cannot - a range that stocks one or both covers those calls.
Choosing sizes for a starter range
Most demand concentrates in the middle: 5x100 and 6x100 carry the everyday work, with 3x75 for the small jobs. A starter range of four to six sizes in the 5-6 mm class plus one 3 mm covers household and trade counters; the long 6x150 and 6x200 blades are the specialist adds. Cartons pack 360 pieces in the smaller sizes and 240 in the larger - so the size split decides both the shelf plan and the freight plan.
Planning a screwdriver block for a range? Send the sizes, quantities and destination market through the contact page - the reply quotes per size with its own carton count.
