M20 x 280mm Plain Hex Bolts (DIN 931) - 316 Stainless Steel: Accu.co.uk: Precision Screws
Thread Adaptor M24 Internal Thread x M24 External Thread, Short Version, Chrome-Plated Stainless Brass Extension, Adaptor for Tap Extension, M24 Internal Thread to M24 External Thread, Short Version 13 mm (Includes 1 Sealing