Abby’s Guide > Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) > Discussions > Honda HS928TCD auger shear pins - two types available
Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions |
|
Underdog
Joined: Oct 18, 2008
Points: 332
|
|
Re: Honda HS928TCD auger shear pins - two types available
Reply #12 Jan 23, 2011 9:39 am |
|
The Canadian Ebay seller responded to my question regarding the "grade" or hardness of these replacement pins; " Hello these will fit the Hs 624. The grade is the exact replacement grade as specified by honda for this application. They would be commonly known as grade 8.8 metric." Can anyone tell what a "metric grade" might be?
|
Bill_H
Location: Maine
Joined: Jan 12, 2008
Points: 354
|
|
Re: Honda HS928TCD auger shear pins - two types available
Reply #21 Jan 23, 2011 12:11 pm |
|
There are grading systems for bolt strength in both SAE and metric. SAE are tested in PSI, metric in MPa. Unmarked: minimum yield strength is 57,000 PSI, metric unmarked is 640 MPa. Minimum tensile strength for these are 74,000 psi or 800 MPa. Unmarked bolts are untreated low or medium carbon steel. Grade 5 and metric 8.8 are medium carbon steel, heat treated and tempered. Grade 8 and metric 10.9 and 12.9 are heat treated and tempered alloy steel. The higher the grade, the stronger the bolt. You want shear pins to be weak. They're supposed to break. The stronger they are, the more stress you apply to parts that are not designed for it. Repeated stresses will cause failure.
This message was modified Jan 23, 2011 by Bill_H
Who the hell let all the morning people run things?
|
|
|