Tapping/Drilling Screw
A tapping or drilling screw is a type of fastener designed to create its own mating thread as it is driven into a pre-drilled hole. Unlike traditional screws that require a pre-existing thread in the mating material, tapping screws feature a sharp, self-drilling point and threads along the length of the shaft.
These screws are commonly used in applications where it is not practical or possible to tap a pre-existing thread, such as in thin sheet metal, plastic, or wood. Tapping screws are available in various head types, including pan, flat, oval, and hexagonal heads, and may feature different drive types such as Phillips, slotted, or Torx.
The design of tapping screws allows for efficient and convenient fastening without the need for tapping or threading equipment. They are widely used in construction, automotive, electronics, and other industries where a reliable and secure fastening solution is required. Tapping screws are available in different materials, including steel, stainless steel, and brass, to suit various application requirements.
Cross-recessed pan head tapping screw
Head Type: Pan head (rounded, protruding head with a flat top surface)
Drive Type: Cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M2 to M6; lengths range from 6 mm to 50 mm.
Application: Commonly used for general-purpose fastening in metal or wood assemblies where a low-profile head is desired.
Material: Typically made from steel, stainless steel, or other corrosion-resistant alloys.
Cross-recessed brazier head tapping screw
Head Type: Brazier head (slightly rounded head with a larger diameter than pan head)
Drive Type: Cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M2.5 to M6; lengths range from 8 mm to 60 mm.
Application: Suitable for fastening metal sheets, thin materials, or plastic where a larger head provides better load distribution and surface contact.
Material: Steel, stainless steel, or other corrosion-resistant materials.
Cross-recessed countersunk head tapping screw
Head Type: Countersunk head (cone-shaped head with a flat top surface)
Drive Type: Cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M2 to M6; lengths range from 8 mm to 60 mm.
Application: Used for flush or recessed fastening in applications where the screw head should sit flush with the surface or be hidden.
Material: Commonly made from steel, stainless steel, or other corrosion-resistant materials.
Hexagon flange head tapping screw
Head Type: Flanged head with a hexagonal shape around the perimeter
Drive Type: Typically hexagonal (requires a wrench or socket)
Sizes (Dia, Length): Diameter ranges from M3 to M8; lengths range from 10 mm to 70 mm.
Application: Provides a larger bearing surface and increased wrenching area, suitable for applications requiring high torque or load-bearing capacity.
Material: Steel, stainless steel, or other corrosion-resistant alloys.
Cross-recessed round head wood tapping screw
Head Type: Countersunk head (cone-shaped head with a flat top surface)
Drive Type: Cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M2.5 to M6; lengths range from 10 mm to 75 mm.
Application: Used for flush or recessed fastening in wooden applications where the screw head should sit flush with the surface.
Material: Steel, stainless steel, or other corrosion-resistant materials.
Cross-recessed countersunk head wood tapping screw
Head Type: Countersunk head (cone-shaped head with a flat top surface)
Drive Type: Cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M2.5 to M6; lengths range from 10 mm to 75 mm.
Application: Used for flush or recessed fastening in wooden applications where the screw head should sit flush with the surface.
Material: Steel, stainless steel, or other corrosion-resistant materials.
Self drilling tapping screw
Head Type: Varies depending on the specific design (pan head, countersunk, etc.)
Drive Type: Typically cross-recessed (Phillips or Pozidriv)
Sizes (Dia, Length): Diameter ranges from M3 to M8; lengths range from 12 mm to 100 mm.
Application: Designed for drilling and tapping in a single operation, commonly used in metal-to-metal or metal-to-wood applications where pre-drilling is impractical or time-consuming.
Material: High-strength steel or stainless steel, often coated for additional corrosion resistance.
SURFACE TREATMENT OF TAPPING SCREWS
Zinc Plating: Zinc plating is one of the most common surface treatments for tapping/drilling screws. It provides a thin layer of zinc coating, offering corrosion resistance and a shiny finish. Zinc-plated screws are widely used in various applications due to their cost-effectiveness and versatility.
Black Oxide Coating: Black oxide coating, also known as blackening, is a chemical conversion coating that creates a black surface layer on the screw. It provides mild corrosion resistance and enhances the appearance of the screw. Black oxide-coated screws are popular in applications where aesthetics are important.
Hot-Dip Galvanizing: Hot-dip galvanizing involves immersing the screws in molten zinc, creating a thick and durable zinc coating. Galvanized screws offer excellent corrosion protection, especially in harsh environments such as outdoor applications and marine environments.
Passivation: Passivation is a chemical treatment used primarily for stainless steel screws to remove surface contaminants and enhance corrosion resistance. It forms a protective oxide layer on the surface of the screw, reducing the risk of rusting and staining in corrosive environments.
Electroplating: Electroplating involves depositing a thin layer of metal, such as nickel or chrome, onto the surface of the screw using an electric current. This process provides corrosion resistance and can also improve the appearance of the screw, offering options for decorative finishes.