Hilka Pro-Craft Metric O-Ring Set 3-50mm 419 Pcs (27385)

Hello, thank you for the question. The 'O' rings are made from Nitrate butadiene rubber. Regarding food grade this is hard to clarify without knowing the specific application. They would be suitable for say a tap but are not suitable for human consumption. Regards, Hilka Tools

Hello, thank you for the question. The 'O' rings are made from Nitrate butadiene rubber. These O-rings are both oil and petrol resistant, and not effected by high temperatures. These would be suitable. Regards, Hilka Tools

Hello, thank you for your query. The 'O' rings would be suitable for the majority of garden hose joints. The set container the followings sizes if you wanted to cross check your item. All measurements to follow will be Inside Diameter x Thickness x Quantity. 3 x 1.5 x 20, 4.4 x 2 x 20, 5 x 2 x 18, 7 x 1.5 x 23, 10 x 1.5 x 23, 13 x 1.5 x 23, 10 x 2.5 x 14, 11 x 2.5 x 13, 13 x 2.5 x 14, 14 x 2.5 x 13, 16 x 2.5 x 14, 18 x 2.5 x 14, 19 x 2.5 x 13, 21 x 2.5 x 14, 22 x 2.5 x 13, 18 x 3.5 x 10, 20 x 3.5 x 10, 22 x 3.5 x 10, 23.5 x 3.5 x 10, 25 x 3.5 x 10, 26.5 x 3.5 x 10, 28 x 3.5 x 10, 30 x 3.5 x 10, 31 x 3.5 x 10, 33 x 3.5 x 10, 34.5 x 3.5 x 10, 36 x 3.5 x 10, 38 x 3.5 x 10, 41 x 3.5 x 10, 44 x 3.5 x 10, 47 x 3.5 x 10, 50 x 3.5 x 10. Kind regards, Hilka Tools.

Hello, thank you for your query. The 'O' rings would be suitable for the majority of kitchen taps. Kind regards, Hilka Tools.

Hello, thank you for your query. The 'O' rings are made from Nitrate butadiene rubber. Looking online there appears to be specific o-rings for specific makes / models. As a combi boiler involves gas i can only recommend you consult the manufacture of the combi boiler and fit OEM parts. Kind regards, Hilka Tools.