Help with understanding bolts please??

All about bolts (Author: Nino)
M5 x 6 means:
M5 is the size of the thread in millimeters: here it`s 5 millimeters of outside diameters.
6 refers to the length of the thread in millimeters: here it is 6 millimeters.
So M6 x 15 for example means a 6 millimeter diameter thread which is 15 millimeters long.

BOLT TUNING:

Aluminium Titanium
Chainring bolts − 30 g − 15 g 2x5 pcs
− 24 g − 12 g 2x4 pcs
Crank fixing bolts − 15 g − 10 g
F-derailer − 5 g − 2 g 2 main bolts
R-derailer − 10 g (ca.) − 4 g (ca.) hanger bolt, cable stop bolt, pulley wheel bolts
A-head cap bolt − 4 g − 2 g M6x20 mm
Bottlecage bolts − 7 g − 4 g 4 pcs M5x10 mm (Al = 3 g / Ti = 6 g / Steel = 10 g)
Brake lever bolts − 5 g
Canti brake bosses on frame − 8 g 2 pcs (typical steel bosses weigh around 24 g)
Canti brake bosses on frame − 6 g 2 pcs (Manitou Ti: 12 g / RockShox SID steel: 18 g / Manitou steel: 21 g)
Stem − 5-10 g 4-6 pcs
Seatpost − 3-8 g (ca.) 1-2 pcs
V-Brake canti bolts − 11 g − 6 g 4 pcs M6x15 mm
V-Brake cable fixing bolts − 5 g − 3 g 2 pcs M5 or M6x8 mm
V-Brake brakepad fixing nuts − 10 g 4 pcs M6
V-Brake brakepad carrier bolts − 8 g 4 pcs (Ti = 12 g / Steel = 20 g)
Ti bolt-on axles instead of QR − 70 g typical steel QR levers 120 g, bolt-on axles Ti = 48 g / steel 65 g
Cassette Lockring − 10 g Steel 14 g / Al 4 g
Pedals − 10 g my Corratecs had 8 steel bolts
Pedal axles − 70 g

The only place you need the added strength of Titanium is at the stem and the seatpost.
All other bolts can be out of Aluminium which is also a lot cheaper than Ti.

Carbon (savings over aluminium):
A-head spacer − 6 g / 10 mm (Al = 10 g / 10 mm , Carbon = 4 g / 10 mm)


V-BRAKE TUNING:
CrMo Ti Al Max. saving
4 Canti-bolts M6x15 mm 16 g 10 g 5 g − 11 g (Al)
4 padcarrier bolts 20 g 12 g − 8 g (Ti)
4 pad fixing nuts M6 14 g 9 g 4 g − 10 g (Al)
2 Cable fixing bolts M6x8 mm (Avid) 8 g 5 g 3 g − 5 g (Al)
Total possible savings: − 34 g


Example for maximum possible BOLT-TUNING on a MTB:
ALUMINIUM:
Chainring bolts (2x5pcs) -30 g / (2x4 pcs) –24 g
Crank fixing bolts -15 g
F-derailer (2 main bolts) -5 g
R-derailer (hanger bolt, cable stop bolt, pulley wheel bolts) ca. -10 g
A-head cap bolt (M6x20 mm) -4 g
Bottlecage bolts (4 pcs M5x10 mm) –7 g ( Al = 3 g / Ti = 6 g / Steel = 10 g)
Brake lever bolts –5 g
V-Brake canti bolts (4 pcs M6x15 mm) –11 g
V-Brake cable fixing bolts (2 pcs M5 or M6x8 mm) –5 g
V-Brake brakepad fixing nuts (4 pcs M6) –10 g
Cassette Lockring –10g (steel 14 g / Al 4 g)

TITANIUM:
Seatpost clamp bolt –3 g
Canti brake bosses on frame (2 pcs.) : -8 g
Canti brake bosses on fork (2 pcs) -6 g
V-Brake brakepad carrier bolts (4pcs) -8 g
Stem (4-6 pcs) 5-10 g
Seatpost (1-2pcs) ca. 3-8 g

Total possible savings: ca. 150 g

Remember:
Titanium is about 1/3 lighter than steel.
Aluminium is 1/3 the weight of steel and ½ the weight of Titanium.
Carbon is about ½ the weight of aluminium


This was put together by nino some time ago. Good info. for starters.