Why do self-tapping screws have different caps (varieties, disadvantages of self-tapping screws)

Fasteners are used everywhere. The most popular are self-tapping screws. They are easy to distinguish by their elongated threaded body and a sharp end. On top of the fasteners - a hat with slots for a bit, a screwdriver.

The main types of self-tapping screws: for wood, metal, drywall, for roofing. Hardware also differ in color (black, with a yellowish tinge or silver). By material of manufacture: high-carbon steel, stainless steel, bimetallic. The coating can be powder paint, yellow or white zinc, phosphate.

There are dozens of different types of hats (heads). Much depends on the shape: the durability of the fasteners, aesthetics and reliability.

Secret hat

Such fasteners look great, which allows them to be used for finishing work or when assembling furniture.

Most often, self-tapping screws are used when working with wood. To completely hide the head of the fastener in the tree, the self-tapping screw must be drowned by 1 mm. Then disguise the special place. putty on wood.

There are self-tapping screws with a drill and a countersunk head. They are used for fastening in metal. A sharpened drill goes into the metal without additional drilling a hole.

There is a similar fastener with a half-countersunk head. Such a self-tapping screw has a protrusion on top. It is used for fastening thin metal or profiled sheet.

Fasteners with press washer

Self-tapping screws with a flat cast washer that presses the sheet material well. There are 2 types of such self-tapping screws: with a sharp tip and fasteners with a tip in the form of a drill.

The first type of self-tapping screw is made of high quality steel (highest strength). The surface is treated with a thin layer of zinc. A cross-cut head is fused by welding. Most often, such fasteners are used in woodwork.

The second type, with a drill bit, is made of high quality zinc-coated steel. The only difference is in the core with the shape of the drill. Great for metalworking.

The presence of a press washer helps to obtain a particularly strong, tight connection of materials.

Semicircular hat

Fasteners are good for assembling auto parts, machine tools, and other equipment. Used for those cases when there is no need for a secret version.

Suitable for wood, metal, plastic, gypsum fiber and other materials. If you use a dowel, it adheres well to brick, concrete, stone. Manufactured from durable galvanized steel.

Hex head

Top molded washer. You can screw in, unscrew the fasteners with a key. If combined with a dowel, it can be used for concrete, brick, stone. Suitable for assembling gazebos, wooden structures.

Cylinder head

Above, a smooth cylinder without edges.

There is a turnkey hexagon inside the cap. Cons: You need to pre-drill a hole for such a fastener. Made from durable stainless steel. This allows them to be used for thin metal sheets.

Straight slot

An old type of slot, which is now discarded due to poor fit with a screwdriver.

It quickly "licks off" from the tool and then it is problematic to unscrew the screw.

Cross recess Pz or just Z

Has the usual slots and additional under 45 gr. between the main ones.

Torx

The hat has cutouts in the form of a six-pointed star. Used in power tools, machinery, cars, etc.

Anti-vandal self-tapping screw

Unusual holes in the cap. Fasteners can be found in various equipment, elevators, vehicles, fences, etc.

There are many options and varied slots.