!Found! M4.5 x 35mm Hex Cap Bolt for Seat Wanted - Where to buy

[wiggydiggy]

Edit - Now found a spare but will be changing seatpost

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One of my seat bolts snapped on a ride, got home ok but need to replace it. Having difficulty sourcing one so wondered where I might get one?

Its a M4.5 Hex Cap Bolt, 35mm long. I've tried Screwfix/Toolstation/Farnell and they don't stock what I want. Also tried all my usual bike shops but still not.

I've got a new seatpost on order, but was hoping to fix this as seems a waste to chuck the whole thing based on one bolt failing.

 

[ianrauk]

It would be worth giving SJS or Spa Cycles a shout. See if they have anything in stock.

 

[Gillstay]

If you can find a fastners shop near you or online you should be able to get one. I was going to recommend mine but just found they have closed which is a blow.

 

[Gwylan]

One of my seat bolts snapped on a ride, got home ok but need to replace it. Having difficulty sourcing one so wondered where I might get one?

Its a M4.5 Hex Cap Bolt, 35mm long. I've tried Screwfix/Toolstation/Farnell and they don't stock what I want. Also tried all my usual bike shops but still not.

I've got a new seatpost on order, but was hoping to fix this as seems a waste to chuck the whole thing based on one bolt failing.



View attachment 769285

View attachment 769287

My shed. Off to locate I'll pm if I find one

 

[wiggydiggy]

It would be worth giving SJS or Spa Cycles a shout. See if they have anything in stock.

I did search their website but I will phone them I think, both good companies.

If you can find a fastners shop near you or online you should be able to get one. I was going to recommend mine but just found they have closed which is a blow.

Nothing came on their website but I can can phone them, reminded me to check my local hardware store also.

My shed. Off to locate I'll pm if I find one

If you had one happy to send £££ for it

 

[Pblakeney]

Search on Google but whatever you do, do not buy from a cycle shop. Way overpriced.
Buy from a hardware retailer, and specify A4 preferably, or A2 stainless steel. Ones I've bought cost a few pence each.

 

[Way-Out-West]

Are you positive it's 4.5mm and not 4mm or more likely 5mm. Bottle cage bolts are usually 5mm so it might be worth checking with one from your bottle cage.

 

[wiggydiggy]

Search on Google but whatever you do, do not buy from a cycle shop. Way overpriced.
Buy from a hardware retailer, and specify A4 preferably, or A2 stainless steel. Ones I've bought cost a few pence each.

Is it A4 the size, or something else? My 4mm Hex is too small, it only fits the 4.5mm Hex?

Are you positive it's 4.5mm and not 4mm or more likely 5mm. Bottle cage bolts are usually 5mm so it might be worth checking with one from your bottle cage.

Positive. 4mm Hex will spin it, but not to tighten it. 4.5mm fits perfectly.

The seatpost is unbranded, bought second hand from a bike charity, it could well be a bespoke size just from one bike that fitted mine when I called in.

 

[fossyant]

Always worth having a set of M bolts in the 'spares file - you can get a box of assorted sizes and lengths for less than £10

 

[Way-Out-West]

Is it A4 the size, or something else? My 4mm Hex is too small, it only fits the 4.5mm Hex?


Positive. 4mm Hex will spin it, but not to tighten it. 4.5mm fits perfectly.

The seatpost is unbranded, bought second hand from a bike charity, it could well be a bespoke size just from one bike that fitted mine when I called in.

The size of the hex head doesn't necessarily tally with the diameter of the bolt shaft.

 

[wiggydiggy]

Always worth having a set of M bolts in the 'spares file - you can get a box of assorted sizes and lengths for less than £10

📰STOP PRESS🗞️

Just checked the shed again, always worth a second look, and found !1! single M4.5 x 37.5mm. Seems to fit the seatpost head ok and I'll try fitting back onto the seatpost and saddle later. I did notice though I've lost a washer like part that helps it hold onto the seatpost head, a washer will do for now but will change the post when the new one arrives as it seems like a bit of a bodge.

 

[wiggydiggy]

Is it defo M4.5 thread? Have you tried and standard M5 or M4 bolt to double check, M4.5 is quite rare and the head side is irrelevent its the thread diameter & and pitch that counts

Definately a M4.5 head, my 4.5mm Hex will turn it but not tighten it. The one I've found is also M4.5 and the right thread diameter/pitch.

The washer is mine instead of the little black gimble that I've lost from the broken bolt.


Might have to add a couple more washers in case its too long


Bottom

 

[Pblakeney]

Is it A4 the size, or something else? My 4mm Hex is too small, it only fits the 4.5mm Hex?

A4 refers to the grade (quality) of stainless steel. A4 is marine grade and therefore more corrosion resistant. A2 is a decent enough substitute.

 

[T4tomo]

A4 refers to the grade (quality) of stainless steel. A4 is marine grade and therefore more corrosion resistant. A2 is a decent enough substitute.

wont it be 4 times the size though?

...I'll get my (paper) coat...