8g (4.20mm) Zinc Yellow Hex Flange (1/4″) Coarse Metal Self Drilling Screws

Product Features

• Hex Head Self Drilling Screws have a drill point that create their own hole and thread in one action. Commonly used for HVAC duct, clips and brackets, carports, sheds, garages, steel framing, fencing and general construction.
• Easy to install using a 1/4″ Socket for 8 gauge, 5/16” Socket for 10 and 12 gauge and 3/8” Socket for 14 gauge or appropriate driver bit in a power tool.
• Material / Coating: Zinc Yellow plated refers to the colour of the chromate that is applied after zinc has been applied. Yellow chromate increases the overall protection of the finish. Commonly used in the automotive industry. The coating is intended to be used internally as it only offers an average level of protection against corrosion. If you want a fastener that will withstand the outdoor elements choose from our Stainless steel or Galvanised range
• What does TPI stand for?: TPI stands for “threads per inch” which literally means the number of threads within each inch on a screw, a bolt, or a fastener. To determine the TPI of a screw, count the number of threads contained within an inch of length on the fastener. If the screw is less than an inch count ½” of an inch and multiply by 2
• Length of Thread: Always choose a self driller with enough threads to fully engage in the base metal. For attachments to 1/4″ base steel, a self-drilling screw should have at least 1/4″ of threads. It is helpful, but not critical, that the threads also engage in the material being fastened. The head of the fastener provides the bearing force for the material being fastened, while the threads provide the clamping force in the base material
• Thread Length: Thread lengths have been included as a guide only. Due to stock being sourced from multiple suppliers variations do exist. We will always ship the same brand and thread length but subsequent orders may be another brand and the thread length may be different. If thread length is critical, please message us prior to ordering as we are happy to physically check our stock and advise prior to shipping
• Drill Point Style: A twist drill style hardened point for fast driving into light gauge sheeting, cladding panels, sections and assemblies. The length of the drilling flutes determine the amount of drilling swaft that can be expelled and therefore the depth of metal can be drilled
• How to measure the length of a Metal Screw: Fastener length is generally measured from the point where the surface of the material will be when the fastener is installed to the end of the fastener. Thus, fasteners with heads that sit above the surface are measured from under the head to the end of the fastener, while fasteners that sit flush with the surface are measured from the top of the head to the end of the fastener
• Need a Driver Bit?: A large range of suitable driver bits are available in the “Driving” section of our website
• Measurements: Every effort has been made to ensure all measurements on our site are accurate and to the relevant standard, they should only be used as a guide. If you see a problem with our specifications please contact us
• Dimensions: Our stock is sourced from various suppliers, therefore differences may exist between batches such as height, width, visible stamped markings, appearance or actual finish
• Photos: are of the product but may not be the actual diameter, length, thread length, colour you require, always refer to the size in the description and additional specifications data provided prior to ordering
• Updating our site: If you see any problems with any of our specifications or you require additional information please contact us
• Disclaimer: Technical data and specifications were researched and compiled from numerous industry sources for the sole purpose of providing basic information. All material is advisory only and its use by anyone is entirely voluntary. Reliance on it for any purpose by anyone is at the sole risk of that person, and Bolt and Nut Australia is not responsible for any loss, claim or damages arising therefrom. In developing this information, Bolt and Nut Australia has made a determined effort to present it accurately

Product Specifications

• System of MeasurementScrew Gauge
• ProductSelf Drilling Metal Screw
• Head TypeHex Flange Head
• Size8g (4.20mm)
• Thread Pitch18 TPI
• Thread DirectionRight Hand
• Thread TypeCoarse
• Corrosion Protection LevelModerate
• Class GradeClass 2
• MaterialHardened Steel
• FinishZinc Yellow
• NEO Sealing WasherNo
• Product Diameter (d)4.00 – 4.20mm
• Head Diameter (a)9.70 – 10.00mm
• Screw Length (l)Length measurement is from under head to end of drill point
• Head Height (h)4.00mm
• Min to Max Steel Thickness0.75 – 2.50mm
• Drive Size (as)1/4″
• Drive TypeHex
• Screw PointDrill Point
• Closest size in mm4.20mm
• Closest size in imperial0.17″
• Standard Made ToAS3566
• BrandHobson Engineering
• Alternative BrandsTower | Bremick Fasteners