{"product_id":"1-gang-35mm-galvanised-steel-back-box","title":"1 Gang 35mm Galvanised Steel Back Box","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThis Knightsbridge 1-gang 35mm galvanised steel back box provides the recessed housing for a single-gang electrical accessory, measuring 73mm square with a 35mm recess depth. The box is pressed from 1mm-thickness galvanised steel, giving corrosion resistance in damp or condensation-prone environments where standard metal boxes may rust over time.\u003c\/p\u003e\n\u003cp\u003eDesigned for installation into masonry, plasterboard and timber stud walls, the box has one fixed mounting lug at the top and one adjustable lug at the bottom, allowing the faceplate fixing points to be aligned horizontally even when the box itself sits slightly off-square in the wall cavity. An integrated earth terminal inside the box provides a bonding point for the earth conductor. 20mm knockouts on the sides and rear accept standard conduit entries and cable glands.\u003c\/p\u003e\n\u003cp\u003eThe 35mm depth accommodates deeper devices such as dimmer modules, USB charging sockets, or installations where multiple cables terminate in the same box and additional space is needed behind the faceplate. The galvanised finish on the steel provides a zinc coating that protects the base metal from oxidation in kitchens, bathrooms, utility rooms and external covered installations where moisture ingress is a concern.\u003c\/p\u003e\n\u003ch5\u003eSpecification\u003c\/h5\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeight\u003c\/td\u003e\n\u003ctd\u003e73 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWidth\u003c\/td\u003e\n\u003ctd\u003e73 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecessed Depth\u003c\/td\u003e\n\u003ctd\u003e35 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003eSteel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEarth Terminal\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003eDownloads\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/products_2795606_datasheet.pdf\" target=\"_blank\"\u003eProduct Specification Sheet\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003eFrequently Asked\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between 25mm and 35mm back boxes?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA 25mm box is the standard depth for most single-gang switches and sockets. A 35mm box provides an extra 10mm of recess depth, which is needed for dimmer switches, USB sockets, smart switches, or installations where multiple cables terminate in the same box and additional clearance is required behind the faceplate.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this be used in bathrooms?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The galvanised steel finish provides corrosion resistance in damp environments. The box should still be installed in compliance with BS 7671 wiring regulations, which specify minimum distances from water sources and zoning requirements for bathroom electrical installations.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat size wall opening is needed?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe box measures 73mm square externally. A wall opening of approximately 75-76mm square is typically cut to allow the box to be recessed into the cavity with minimal gap around the edges, which is then filled during plastering or making good.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre the lugs adjustable for levelling?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe top lug is fixed. The bottom lug is adjustable, allowing the faceplate fixing points to be aligned horizontally even when the box sits slightly off-square in the wall. This prevents faceplates from appearing tilted after installation.\u003c\/p\u003e","brand":"Knightsbridge","offers":[{"title":"Default Title","offer_id":45293883719947,"sku":"GSK35","price":1.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/177334_2c24b63d-9d75-48bb-a8ff-b87bc0937de0.jpg?v=1714665499","url":"https:\/\/niori.co.uk\/products\/1-gang-35mm-galvanised-steel-back-box","provider":"Niori","version":"1.0","type":"link"}