Black Phosphate Drywall Screws 3.5×25mm common problems and solutions, just read this article

Common problems and solutions for black phosphate drywall screws

Problem phenomenon	Cause analysis	Solution
Black Drywall Screws head slips (cross groove damaged)	Bit mismatch/drill speed is too high	Replace PH2 bit, reduce speed and apply vertical pressure
Gypsum board surface cracks	Drive too deep or force too large	Control the torque of the electric drill, and repair the damaged parts with putty
Nail body bends or breaks	Encounter hard objects (such as buried pipelines in the wall)	Avoid pipeline areas and use hardened drywall nails
Nail head protrudes from the board surface	Clutch is not used/manual screwing force is insufficient	Re-adjust the torque of the electric drill, and the repair nail needs to be driven in at an angle of 45°
Rust spots on the nail head seep out later	Anti-rust putty is not applied/humid environment	Remove rust stains → Apply anti-rust paint → Re-apply putty
Slip on light steel keel	Ordinary nails are not hard enough	Replace with self-tapping drywall screws or pre-drill 0.5mm guide holes

Visual inspection: All nail heads are evenly sunk into the board surface, without missing nails or skewness.

Hand touch test: There is no bulge at the nail head, and the gypsum board and the keel fit together without gaps.

Spacing specification: Screw spacing ≤20cm (edge)/≤30cm (middle), ≥1cm from the board edge.