Here's a list of guide inserts/rings available.
What is the minimum guide insert/ring you would require on your rods? Add line choices for each material in your answer/opinion.
Describe the benefits and faults of each insert/ring as you know it.
Vickers hardness ratings:
Stainless Steel (SS): 400 [b.E.] Chrome: 800-1000 [C.M.] Carbaloy: 1000 [b.E.] Aluminum Oxide: 1200-1400 [b.E., C.M.] Alconite (Fuji): 1300-1500 [Fuji] NanoLite (Titan): 1800 [J.M.] Zirconia: 1000-1400 [M.G.] Zirconia PVD: 1600 [b.E.] SiC: 2200-2400 [b.E., C.M.]