Titanium Bolts has presence of nascent oxide, which starts forming immediately after the titanium bolts and nuts are exposed to air. Due to the presence of this oxide, titanium fasteners show excellent corrosion resistance.
Since Titanium Bolts do not show any signs of pitting, they are widely sued in exterior architectural applications. Titanium screws and nuts with titanium washers are used in the prosthetic devices. Titanium screws are often used in fixtures used for human body like kneecaps, ball joints etc.
In general titanium grade 5 screws and nuts are used for such critical application where pitting is not acceptable. Due to excellent biocompatibility titanium nuts and bolts have a large demand worldwide.
Titanium fasteners with combinations of titanium flanges and titanium pipes are widely used in chemical pressure vessels due to corrosion resistance factors and weight to strength ratio.
Automobile industry uses these lightweight titanium bolts and nuts to reduce the weight of vehicles, which in return provide better transportation.
Armies both navy and military use a lot of titanium alloy fasteners and plates to reduce the weight of armor vehicles and instruments.
Commercially pure titanium and other Titanium Bolts are immune to stress corrosion cracking unless there is a default crack in the presence of stress.
These cracking when occurs in air, forms a protective oxide layer, but when it happens in sea water then there is a probability of stress corrosion cracking.
Embrittlement of solid titanium metal is a problem with Titanium Bolts and titanium alloy fasteners.
Below chart gives a complete idea about titanium grades available in stock for production of titanium fasteners.
| UNS No. | Fasteners Trade Names | C | Fe | O | H | N | Ti | Al | Y | V | Sn | Pd | Mo | Ni |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R50350 | Titanium Grade 1 | 0.1 Max | 0.2 Max | 0.18 Max | 0.015 Max | 0.03 max | Balance | – | – | – | – | – | – | – |
| R50350 | Titanium Grade 2 | 0.08 Max | 0.3 Max | 0.25Max | 0.015max | 0.03 Max | Balance | – | – | – | – | – | – | – |
| R50350 | Titanium Grade 3 | 0.08 Max | 0.3 Max | 0.35Max | 0.015max | 0.05 Max | Balance | – | – | – | – | – | – | – |
| R50400 | Titanium Grade 4 | 0.08 Max | 0.50 Max | 0.4Max | 0.015Max | 0.05Max | Balance | – | – | – | – | – | – | – |
| R50550 | Titanium Grade 5 | 0.08 Max | 0.40 Max | 0.2Max | 0.125Max | 0.05Max | Balance | 5.5-6.75 | 0.005Max | 3.5-4.5 | — | — | — | — |
| R50700 | Titanium Grade 6 | 0.08 Max | 0.50 Max | 0.20 Max | 0.020 Max | 0.05Max | Balance | 4.5-5.75 | 0.005Max | 2.0-3.0 | – | – | – | |
| R56400 | Titanium Grade 7 | 0.08 Max | 0.30 Max | 0.25 Max | 0.015 Max | 0.03Max | Balance | – | – | – | – | 0.12-0.25 | – | – |
| R54520 | Titanium Grade 9 | 0.08 Max | 0.25 Max | 0.15 Max | 0.015 Max | 0.03 Max | Balance | 2.5-3.5 max | – | 2.0-3.0 | – | – | – | – |
| R52400 | Titanium Grade 10 | 0.08 Max | 0.20 max | 0.18 Max | 0.015 max | 0.03 Max | Balance | – | – | – | – | 0.12-0.25 | – | – |
| R56400 | Titanium Grade 11 | 0.08 Max | 0.30 Max | 0.25 Max | 0.015 Max | 0.03 Max | Balance | – | – | – | – | – | 0.2-0.4 | 0.6-0.9 |