Register free!
Search
 
     

The Green Industry's Resource Center


Click for Weather
Reply
 
Thread Tools Display Modes
  #1  
Old 07-31-2002, 07:35 PM
gogetter gogetter is offline
Banned
 
Join Date: Jan 2001
Location: Yardley, PA.
Posts: 3,256
A bolt is a bolt is a bolt?

Wasn't sure where to post this one.
Anyway, I just had to replace the blade bolt and nut on my mower. It ran me about $12 to get exact replacement parts from the dealer.

Out of curioisty stopped at hardware store and found same SIZE nut and bolt, BUT, different threads for about $4.

So question is, do the type of threads or thread count matter and if so, why?

The replacement parts had a higher thread count then the nut and bolt at hardware store.
How important are the threads?
Reply With Quote
  #2  
Old 07-31-2002, 07:54 PM
Bob Minney's Avatar
Bob Minney Bob Minney is offline
LawnSite Bronze Member
 
Join Date: Jan 2002
Location: The Hottest driest city next to Hades - Denver Colorado
Posts: 1,094
Look at different hardness of the metal in the bolt.
hash marks on the head of the bolt define hardness of metal, I don't remember exact system but no marks = soft metal, more marks= hard
Since the bolt is in a critical area I would make sure that replacement is same quailty.

If its a nut and bolt then using a fine/coarse thread wouldnt matter
__________________
If you want people to notice your faults, start giving advice.
Reply With Quote
  #3  
Old 07-31-2002, 08:13 PM
gogetter gogetter is offline
Banned
 
Join Date: Jan 2001
Location: Yardley, PA.
Posts: 3,256
Thanks Bob, I did see marks as you mentioned. I was wondering what they represented.
Hadn't thought of the 'hardness' factor. Thanks again.
Reply With Quote
  #4  
Old 07-31-2002, 10:00 PM
Lohr Equipment & Wel Lohr Equipment & Wel is offline
LawnSite Member
 
Join Date: Jul 2002
Location: Clarks Summit,Pa
Posts: 17
As far as I know if you add 2 to the number of lines on the head of the bolt,this will give you the grade of bolt.Example,three lines add 2,that is a grade 5 bolt,6 lines add 2 that is agrade eight. This is just my personal opinion but I spend the extra money and buy good American Grade 8 bolts for everything.If it ain't made here I don't want it.
Reply With Quote
  #5  
Old 08-01-2002, 09:30 AM
sdwally sdwally is offline
LawnSite Senior Member
 
Join Date: May 2001
Location: San Diego, CA
Posts: 385
Grade 2 or lower - no marks
Grade 5 - 3 marks
Grade 8 - 6 marks
There are also higher grade bolts with other markings. A good quality bolt will also have a manufacture's id mark on it also. Without the manufacture's id, you can not be sure of an acurate grade rating. Grade 5 is the standard for normal use. Grade 8 have the applications, but can be to brittle for use everywhere especially if it has a shearing force applied to it.
TPI(threads per inch) have different torque ratings. The more TPI the higher the torque rating. Depending on the application, national coarse(NC) is more widely used, however a national fine(NF) can be substituted with out any problems normally. Metrics come in standard, fine, and extra fine TPIs. Most widely used are standard and fine TPIs.
Metrics are rated also using a different identifiers. 8.8, 10, and 12 as I recall. The standard rating depends on the sized bolt to be used. They also should have a manufacture's id mark.
__________________
Clay Walsten
ET III
Developed Regional Parks
City of San Diego

We enrich lives through quality parks and programs.
Reply With Quote
  #6  
Old 08-10-2002, 01:13 PM
bob's Avatar
bob bob is offline
LawnSite Platinum Member
 
Join Date: Dec 1999
Location: DE
Posts: 4,241
What kind of mower is the bolt from?
__________________
Bob

If you choked a Smurf, what color would it turn?

I'd give my right hand , if I could be ambidextrous!
Reply With Quote
  #7  
Old 08-10-2002, 09:44 PM
edward hedrick edward hedrick is offline
LawnSite Senior Member
 
Join Date: Jan 2001
Location: Trumbull,ct
Posts: 869
I worked for a local Industrial hdw store. Sold 5/8x11x9" grade

5 for $2.50. Local Scag dealer bought from us sold it for $10
Reply With Quote
  #8  
Old 08-10-2002, 10:00 PM
The Mowerdude The Mowerdude is offline
LawnSite Senior Member
 
Join Date: Jul 2002
Location: Nashville, Tn.
Posts: 372
Hey, Edward

I think that's a little scary, because all of my Scags and Great Danes came with grade 8.

I'm glad you told me that. In the future, I'll be more aware of what I'm buying.
Reply With Quote
  #9  
Old 08-11-2002, 01:52 AM
gogetter gogetter is offline
Banned
 
Join Date: Jan 2001
Location: Yardley, PA.
Posts: 3,256
Quote:
Originally posted by bob
What kind of mower is the bolt from?
Bob, it's my 36" Exmark metro. This is the second bolt/nut I've stripped somehow. They went on fine, but wouldn't come off. Think I may have over tightened them.
Ordered a torque wrench the other day.

Thanks for all the info in the replies guys. Interesting stuff.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump





Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ©1998 - 2012, LawnSite.comô - Moose River Media
All times are GMT -4. The time now is 05:54 AM.

Page generated in 0.09346 seconds with 7 queries