STAINLESS STEEL POZI FLANGED POLYTECH 30

Pozi Flanged Polytech 30 — The integral flange under this screw's head does the job of a separate washer, spreading clamping load over a noticeably wider area than a plain pan head — useful wherever the plastic is thinner, softer, or more prone to marking under concentrated pressure, since a standard head can otherwise dimple or crack the surface as it's tightened. It uses the same Polytech 30 thread-forming profile as the rest of this sub-range, displacing plastic in the pilot hole to form its own mating thread rather than needing a pre-tapped boss, and the Pozidriv recess gives reasonably good resistance to cam-out for general assembly work. Typical uses include softer thermoplastic housings, thin-walled covers, cable management components, and any plastic assembly where a separate flat washer would otherwise be added to prevent the head pulling through. Because the flange is built in, it also removes one loose part from the assembly process, which is a real benefit on manual lines where a dropped or missing washer can hold up a build. Deciding between a flanged head and a plain pan head largely comes down to how the plastic behaves under load: if trial assembly with a standard pan head shows the plastic stress-whitening, dimpling, or cracking around the fixing point, moving to the flanged version is generally a simpler fix than changing the plastic grade or wall thickness. The choice between the Polytech 30 and Polyfix 45 thread ranges follows the same logic as elsewhere in the category — Polytech 30 suits the wider range of boss and plastic hardness combinations, with Polyfix 45 reserved for cases where Polytech 30 doesn't give clean thread engagement. As with other plastic thread-forming screws, there's no dedicated ISO or DIN thread standard for the profile itself, though the flanged pan head follows the same general built-in-washer geometry used on flanged machine and self-tapping screws elsewhere. Grade should be chosen on the finished assembly's environment: A2 (304-equivalent) for indoor and general enclosure work, A4 (316-equivalent) where the product will see outdoor, marine, or washdown conditions.

FAQs
Does the flange change the required pilot hole size compared with the plain pan head?
No — the flange only affects the bearing area under the head; the thread and pilot hole requirements are the same as the equivalent plain pan head in the Polytech 30 range.

Will a flanged head always stop a soft plastic from cracking around the screw?
It significantly reduces the risk by spreading load over a wider area, but it isn't a substitute for adequate wall thickness or boss design; on very soft or brittle plastics, reviewing the boss geometry alongside the head style gives a more reliable result.

Can I use this screw anywhere a separate pan head and washer combination is currently specified?
In most cases yes, and it typically simplifies assembly by removing a loose part, though it's worth checking that the flange diameter suits the available clearance around the fixing point on the existing design.

Is a flanged head necessary on harder engineering plastics?
Less often — harder, more rigid plastics generally tolerate a plain pan head's bearing pressure without marking, so the flanged version earns its place mainly on softer or thinner-walled components.