Most people think that a bolt is just a bolt. \u00a0It’s just something that’s used to hold two things together and that’s the extent of it. \u00a0Fasteners though are incredibly complex pieces of hardware. \u00a0They are manufactured using different materials, thread types, lengths, and a plethora of shapes and sizes. \u00a0They have different coatings, classes of fit, and what I want to talk about the grades.<\/p>\n
Right, you want to just identify the grades of the bolts you have. \u00a0Okay, pretty simple really. \u00a0If you don’t have any bolts on hand take a quick trip to the hardware store and have a look at their selection.<\/p>\n
Bolt grading is used to identify the strength of a bolt. \u00a0 Many fasteners, especially the smaller sizes, are not normally graded. \u00a0I’m writing this from North America so I’m very well used to the ASTM A325 ratings for bolts and will primarily using those as a reference. \u00a0I’ve included a couple of metric classes in the table below for reference. \u00a0Fasteners have special markings not only on the screw head portions but also on the nuts. \u00a0If you are replacing a graded fastener, ensure that you do so with the same or higher grade.<\/p>\n
Since there are so many different grades and fasteners, and to be honest, they look all the same at a quick glance that it is critical that the manufacturers identify the properties of the fasteners.<\/p>\n
Screws are marked on the top of their heads. \u00a0The exception being small, or slotted\/recessed head fasteners as there is no room. \u00a0A head that has no markings should be considered a Grade 2.<\/p>\n
[table id=5 \/]<\/p>\n
Understanding what some of the terms in the table above you may wonder what it all means. \u00a0Or you may just think, dude, you are such a dork… \u00a0For me its a little of both. \u00a0I like to fully understand the reasons why I use some things. \u00a0Getting into the math and info below, for our purposes as droidbuilders and where we typically operate at, there really isn’t any need for us to use higher than grade 2 bolts and be done with it. \u00a0I personally use grade 8 as I know there isn’t anything I can do with my droid that will damage the fasteners \u00a0without completely obliterating the droid.<\/p>\n
Anyhow, lets continue on with some additional terms that are just good to know.<\/p>\n
This is sometimes known as the proof load<\/strong><\/em>. \u00a0This is the tension applied load that the fastener can withstand without any indication of permanent deformation or failure. \u00a0Rule of thumb this is usually calculated at 90-93% of the minimum yield strength.<\/p>\n This is the MAXIMUM tensile applied load the fastener can hold prior to fracture. \u00a0In plain talk, its how much force is required to pull the two items apart before it breaks.<\/p>\n Is the stress at which a predetermined amount of permanent deformation occurs. \u00a0The amount of permanent deformation can be up to 0.2%, anything higher and it fails. The yield strength is what I would consider the most important thing to consider in what fastener chosen.<\/p>\n story time –\u00a0<\/em>Have you ever tried to remove a bolt that has somehow become slightly bent? \u00a0Remember how much a pain it was getting it undone. Well that’s why you choose a bolt with a high yield strength. That example of the bent bolt show you that more load was applied to the bolt than it was rated for.<\/p>\n Here’s the reality, looking at the yield strength in the chart above, you can certainly see that a Grade 2 bolt is more than sufficient to adequately fasten anything on your droid. \u00a0I literally can’t conceive of anything that your droid could possibly be doing that would rate using anything higher. \u00a0I personally use grade 8, but that has more to do with me not wanting to have to carry a bunch of different stock bolts and just stick to one.<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Most people think that a bolt is just a bolt. \u00a0It’s just something that’s used to hold two things together and that’s<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"give_campaign_id":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[260],"tags":[],"class_list":["post-4462","post","type-post","status-publish","format-standard","hentry","category-skill-builder"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8uQ37-19Y","_links":{"self":[{"href":"https:\/\/droidbuilders.info\/index.php?rest_route=\/wp\/v2\/posts\/4462","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/droidbuilders.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/droidbuilders.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/droidbuilders.info\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/droidbuilders.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4462"}],"version-history":[{"count":0,"href":"https:\/\/droidbuilders.info\/index.php?rest_route=\/wp\/v2\/posts\/4462\/revisions"}],"wp:attachment":[{"href":"https:\/\/droidbuilders.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4462"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/droidbuilders.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4462"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/droidbuilders.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4462"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Tensile Strength<\/h4>\n
Yield Strength<\/h4>\n
Reality Check<\/h3>\n