Pro Tips

Many times we are asked “What grade of bolt should I use ?” Unfortunately, that is a hard question to answer from our side of the counter. We are not architects nor engineers.

However, we can shed light on the basic classifications…

In the American world (a.k.a. SAE) the main classifications are Grades 2, 5, 8, Allen heads, and Stainless.

Grade 2 bolts ( A307) are a standard hardware grade steel. This is the least expensive and most common. They have a tensile strength of 60,000 PSI.

Grade 5 bolts are a heat-treated carbon bolt. Hardened to increase its strength, it’s most commonly found in automotive applications. Grade 5 bolts have 3 evenly spaced radial lines … resembling an airplane propeller. They have a tensile strength of 120,000 PSI

Grade 8 bolts are a heat-treated alloy steel that are hardened more than the Grade 5. Thus, they are stronger and can be used in more demanding situations. Grade 8 bolts have 6 evenly spaced radial lines. Grade 8 bolts have a tensile strength of 150,000 PSI

Allen head bolts can easily be identified as they require the use of an allen wrench. Industry standard allen heads have a tensile strength of 160,000 PSI

Stainless Hex Bolts ….. there are different grades of stainless, but the most common are bolts made in the 303 and 304 series of stainless. Many people think stainless bolts are very hard. This is not true. 300 series stainless is just a tad under a Grade 5 in strength. Usually, a tensile strength in the range of 112,000 to 116,000 PSI.

In the metric world (a.k.a. ISO) the most common bolts are marked with an 8.8, 10.9, or 12.9.

If there are no head markings at all, they are most likely comparable to the SAE grade 2.

The 8.8 is comparable to the SAE Grade 5.

The 10.9 is comparable to the SAE Grade 8.

The 12.9 is comparable to the SAE allen head. 

So, you twist the head off of a bolt, and the shank is embedded in whatever you were working on….now what???

There are tons of articles and ideas floating around on the web on how to deal with this miserable problem and I would suggest spending some time surfing the web to educate yourself on some trick ideas on broken bolt removal.  However, what I am going to outline are the basic steps to take, or you could say these are the “Old School” fundamentals!!!

1. Prepare the face of the bolt to be extracted.  First, grind a smooth flat surface and then use a punch to make a mark dead center.
2. Using a small pilot bit, drill a hole dead center in the bolt. Once you have a hole started dead center, you can now switch to a LEFT HAND drill bit (a drill bit that drills in reverse) Choose as large a bit as possible without damaging the threaded wall of the hole.  Many times a bolt will break loose and come out while you are drilling into it in a reverse direction.
3. If the bolt has not broken free, then insert the screw extractor that corresponds with the size hole you drilled. Use a pair of vise grips to grab the extractor and apply moderate pressure while turning the extractor counter-clockwise. The extractor should bind into the broken bolt and begin backing it out. Be careful not to apply too much torque to the extractor. You DO NOT want to snap the extractor off in the hole.
4. If the bolt still will not break free, about the only other option is to drill a new hole and either tap it to the next size up, or consider going the helicoil route. Either way, it would be best to get help before drilling larger holes. It is possible to reach the point of no return!!!!! 

Every carpenter, mechanic, builder, and home improvement enthusiast has experienced the frustration of breaking a bolt. It only takes one turn too many of a wrench to cause that horrifying “snap.” Without specialized tools, it can take hours or days to remove a broken bolt. Fortunately, all the tools needed to perform the extraction, along with replacement bolts of every kind, are available at hardware stores or at competitive prices on eBay. Simply owning the right equipment is not enough, however. It is crucial to know the recommended procedure for removing a broken bolt, or the entire project is at risk. Even the most experienced consumer may need a refresher.

Tools Needed:

For best results in removing broken bolts, a bolt extractor kit is required. These kits come in various sizes and levels of complexity, ranging from just a few included pieces to sets with dozens of parts. The chart below outlines some of the pieces that are typically included in a bolt extractor kit.
 

An alternative to purchasing a bolt extractor kit is to use a reversible drill and left-hand drill bits. For professional carpenters and mechanics, a kit is a wise investment. For occasional home improvement projects, the drill and bit may suffice.

Removing the Broken Bolt

Once all the tools are assembled, the procedure for extracting the broken bolt can begin. There are five relatively simple steps to achieve the removal of a broken bolt.

1. Flatten the Bolt

A broken bolt leaves a jagged, uneven surface. This can cause the drill bit to move off-center, impeding removal, or can cause the drill bit to break, making the problem worse. Use a metal grinder to smooth out the surface where the bolt broke. If the bolt snapped below the surface, use a metal punch to even out any jagged edges, so the drill bit can make a hole in the center of the broken bolt.

2. Drill a Pilot Hole

Using a small drill bit, make a small hole in the center of the broken bolt. It can be helpful to use a heavy hammer and punch to create a dent in the top of the bolt for the drill to follow. Test the hole to see if it is large enough to insert the extracting bit. If not, drill another hole with a slightly larger drill bit. Start small and work up to larger bits, because if the hole is too big for the extracting bit, removal becomes much more difficult.

3. Insert the Extracting Bit

Place the extracting bit into the hole and secure it to the broken bolt. Use a vise grip to apply moderate pressure while turning the extracting bit counter-clockwise. The bit should bind into the broken bolt. If this proves difficult, tap the extracting bit gently with a hammer to press it into the bolt.

4. Remove the Bolt

Continue to turn the extracting tool counter-clockwise until the broken bolt comes completely out of the surface into which it was stuck. Take time and care during this part of the procedure to avoid breaking the bolt further or damaging the material in which it was embedded.

5. Clean Out the Hole

During the extraction, small metal filings often come off the bolt. These must be thoroughly removed before replacing the broken bolt with a new one. Hold a heavy-duty magnet over the hole to attract the filings and shavings. Spraying a small amount of compressed air into the hole ensures that all debris has been cleared out.

New to the world of using Carbide Burrs???? 

Here are a couple of basic guidelines.

­

General Use

• Adjust speeds as needed for optimum performance. Use slower speeds for harder materials. Use higher speeds for cutting with smaller diameter burrs.
• Do not run above maximum speeds. This can cause premature wear and damage to burr teeth.
• Do not run below minimum speeds. This can cause chipping.
• All other tools and collets should be in good condition.
• Not for use in portable drill motors.
• Apply constant pressure while cutting.

General Recommendations for Solid Carbide Burr Speeds

Diameter       Recommended RPM

1/16             60,000 – 90,000

1/8                45,000 – 50,000

3/16             35,000 – 40,000

¼                     30,000 – 35,000

Use the right Burr for the right job !!!!!

I am often asked about hole saws and what will they cut? Are they any good? How long do they last? Here’s what you need to know!

We carry a high-quality Industrial Bi-Metal Cobalt Hole Saw. The high-speed cobalt teeth are electron beam welded to a steel body. It is this process that enables the teeth to cut faster and stay sharper than the traditional standard hole saw.

The high alloy steel body is shatter-resistant for superior durability. 4/6 variable pitch reduces both vibration and heat generation, allowing for a much smoother cut. They also have a positive rake on the teeth for better chip clearance. Cutting depth is 1 ½”.

These cobalt hole saws cut holes in wood, plywood, plastic, fiberboard, or any machinable metal including: nail-embedded wood, pipe, stainless steel, chrome-moly, etc.

Available in sizes ranging from 5/8” up to 6”

Industry standard sizing for the arbors.

Many times our customers bring us what they think is a bolt from a car that they are working on….. Unfortunately, often these aren’t standard bolts. They are more like a part that the automaker has designed for a specific purpose. So, don’t be surprised if we suggest going back to the dealer or to a junkyard!

Many metric automotive bolts are stamped with numbers, creating a lot of confusion as to the actual grade (hardness) of the bolt. We see bolts with a 9, or a 7, perhaps even a 10 stamped in the head.  These numbers do not give us any insight as to the size or hardness of the bolt. The other common mistake people make is to size their bolt based upon the wrench size. This also leads to misunderstanding the size and hardness of the bolt in question. The three most common Metric Head Markings (hardness) are:

• 8.8    Equivalent to our American Grade 5 hardness.  PSI tensile strength of 120,000.
• 10.9   Equivalent to our American Grade 8 hardness.  PSI tensile strength of 150,000.
• 12.9   Equivalent to our American Allen Head bolts.  PSI tensile strength of 180,000.

Ruining a drill bit is one of the easiest things to do and we see this all the time!  Too much speed and too much pressure are the number one enemies of any cutting tool. We sell very high quality domestic cutting and drilling bits of all kinds; lettered bits, numbered bits, fractional bits, cobalt bits and also carbide burrs. Let me say it again-regardless of the quality, too much speed and too much pressure will ruin the best of bits.

One of the best things you can do is get in the habit of using a drop or two of a good cutting oil. We sell MEGACUT threading and cutting Fluid in 4-ounce, 16-ounce, and 1-gallon bottles and it is also available by the 5-gallon container by special order. This is excellent cutting oil. (meets military spec. MIL-STD-767). Also, let me note that using WD40 is the WORST thing you can use as a cutting fluid. It does NOT cool … it evaporates and can actually trigger heat and friction. So, save the WD40 for another project. Get yourself some MEGACUT, ease up on the speed and the pressure, and you’ll get much better results as well as a longer life span for the drill bit!!!

So, what is what ???

Self Tapping Screws work in most materials, but often can require a pilot hole.  There are 3 different types of thread and point patterns.

Type A: Found on Sheet Metal (Tapping) Screws

Type A tapping screws have coarse threads and gimlet points. They are used in thin metal, resinous plywood, and various composite boards.

Type AB: Found on Sheet Metal (Tapping) Screws

Type AB tapping screws have spaced threads and gimlet points. Like the Type A, they are used in thin metal, resinous plywood, and various composite boards. Type AB screws offer a wider range of applications over Type A screws.

Type B: Found on Sheet Metal (Tapping) Screws

Type B tapping screws have spaced threads and a blunt point with incomplete entering threads. They are used in thin metal, nonferrous castings, resinous plywood, plastics, and various composite boards.

Self Drilling Screws (AKA Tek Screws) are for metal only and do not work well in wood because the hole that they drill in the wood is too large and the screw loses much of its initial holding power.

Teks screws, also known as self drilling screws, drill their own hole in thin sheet metal, heavier gauge metals and other materials, then form close mating threads in the hole. The Teks screw is ideal for automated assembly and reduces or eliminates the need for drill bits or taps. Once the hole is drilled, Teks screws (self drilling screws) tap the hole in the same way as thread forming or thread cutting screws do in a pre-drilled hole. They are also designed to eliminate paint build-up, weld flash, or foreign material that may occur in pre-drilled or pre-punched holes.

Thread Cutting Screws like self tapping screws have a variety of points. They work best in thicker materials as they cut their own threads similar to a Tap.

Also known as Type BT, Type 25 screws have spaced, incomplete tapered threads with a blunt point and tapered entering edges, with one or more cutting edges and chip removal indentations. They are used in plastic, asbestos compositions, and other composites.

Type 23: Found on Thread Cutting Screws

Also known as Type T, Type 23 screws have machine screw threads with a blunt point and tapered entering edges, with one or more cutting edges and chip removal indentations. In this sense they are similar to Type F screws. The cutting edge on the point, however, is broader and deeper than that of the Type F. Type 23 screws are also used in nonferrous castings, steel sheets, plastics, brass, cast iron, etc.

As a young boy, I spent many a day with my dad building wooden sailboats. One of my many jobs was to walk behind him as he drilled holes.  I would then take the brass slotted wood screw that he had given me, drag it across a bar of soap and stick it in the hole he had just drilled. After circling the boat in this fashion, he would then screw them in with his “ Yankee” screwdriver …  (that’s an old school screw gun).  He taught me that soaping the screws made them go in easier with less heat and friction.
     

In this day and age with all the high tech drills and screw guns that flood the market ….. this age old concept is still very applicable!  I have more than a few commercial deck builders that swear by soaping their screws first …… although they don’t have their kids to do it! They have found short cuts. The most logical is this: Buy a plastic bottle of liquid detergent, cut the top off and put the bottle of detergent nearby.  Put the screw onto the end of the magnetic bit, dip it into the detergent and then run it into the deck.  The screw goes in much easier and quicker. You also get more life out of the battery charge and will significantly reduce the chance of snapping off heads.  I have another customer who builds a lot of rustic homes and uses a variety of large and very long lag bolts … 1/2 “, 5/8” and even 3/4 ” diameters … sometimes as long as 24”.  He is a firm believer in soaping the lags before running them in, even though he uses an impact gun.

Old tricks never die, sometimes they just don’t get passed on…..just another reason to stop by Mark’s Bolts.

With a variety of discs available, the R Lock system is a disc for almost every need. The aluminum oxide discs are good for grinding, sanding, deburring and blending on ferrous metals, automotive, plastics, paint, fiberglass and wood. We stock 3 diameters …. 1½”, 2”, and 3”. We have them in 36 grit, 80 grit and 120 grit.

The Non-Woven discs are available in 1½”, 2”, 3”, and 4”

We stock them in coarse, medium, fine, and extra fine.

These high performance products are manufactured from a tight non-woven fiber web with a woven backing. They are impregnated with specially processed Aluminum Oxide grain which offers fast initial cut, high rate of productivity and long life.  They are great for deburring, blending, cleaning and finishing of metal surfaces. Also great for oxidation/rust and gasket removal.

The newest R Lock disc to our inventory is the Silicon Carbide Stripper Disc.  We carry these in 2” and 3” diameters. They have a tough open construction and will not load up. They remove surface coatings and surface contaminants. Ideal for maintenance and machine refurbishing. They are equal to 3M Clean and Strip.

So whatever your next job is….. consider the Quick Change R Lock Disc System……. You will love what they do.

Blind Rivets … (most commonly called pop rivets) are measured by their diameter and then by the specific “grip range”.  

The diameter is based on the diameter of the rivet body.

The “grip” is based on the thickness of the material being riveted. The “Grip Range” is the minimum and the maximum grip that the rivet is intended to be used with.

NOTE ……..It is very important to understand that the maximum grip range is NOT the overall length of the rivet body.

We carry the following sizes in our store.:

• 1/8 rivets …. Which are identified with a starting number 4
• 3/16 rivets …Which are identified with a starting number 6 
•  1/4 rivets …. Which are identified with a starting number 8

The second number is the key to the grip range.
Here is the grip range that corresponds to the second number:

• 2      grips from 1/32 to 1/8
• 4      grips from 1/8 to ¼
• 6      grips from ¼ to 3/8
• 8      grips from   3/8 to ½
• 10    grips from ½ to 5/8
• 12    grips from 5/8 to ¾
• 16    grips from ¾ to 1”

So….. a rivet that is labeled 6-10 would be a 3/16” rivet that would grip material ranging from a minimum of ½ thick, up to a maximum thickness of 5/8.

 A 44 rivet would be 1/8 diameter and can grip from 1/8 to 1/4. 

So there it is!….. Now you can choose the right rivet for the job!

A few times each year we receive calls from fastener suppliers who are in conflict with their customer over the quality of stainless steel bolts and nuts. The customer’s complaint is that during installation the bolts are twisting off and/or the bolt’s threads are seizing to the nut’s thread. The frustration of the supplier is that all required inspections of the fasteners indicate they are acceptable, but the fact remains that they are not working. This problem is called “thread galling.”

According to the Industrial Fastener Institute’s 6th Edition Standards Book (page B-28), Thread galling seems to be the most prevalent with fasteners made of stainless steel, aluminum, titanium, and other alloys which self-generate an oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing – the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out. Carpenter Technologies, the fastener industry’s largest supplier of stainless steel raw material, refers to this type of galling in their technical guide as “cold welding.” Anyone who has seen a bolt and nut with this problem understands the graphic nature of this description.

The IFI and Carpenter Technologies give three suggestions for dealing with the problem of thread galling in the use of stainless steel fasteners:

1. Slowing down the installation RPM speed will frequently reduce, or sometimes solve completely, the problem. As the installation RPM increases, the heat generated during tightening increases. As the heat increases, so does the tendency for the occurrence of thread galling.

2. Lubricating the internal and/or external threads frequently eliminates thread galling. The suggested lubricants should contain substantial amounts of molybdenum disulfide (moly), graphite, mica, or talc. Some proprietary, extreme pressure waxes may also be effective. You must be aware of the end use of the fasteners before settling on a lubricant. Stainless steel is frequently used in food related applications, which may make some lubricants unacceptable. Lubricants can be applied at the point of assembly or pre-applied as a batch process similar to plating. Several chemical companies offer anti-galling lubricants.

3. Using different stainless alloy grades for the bolt and the nut reduces galling. The key here is the mating of materials having different hardness’s. If one of the components is 316 and the other is 304 they’re less likely to gall than if they’re both of the same alloy grade. This is because different alloys work-harden at different rates.

Another factor affecting thread galling in stainless steel fastener applications is thread roughness. The rougher the thread flanks, the greater the likelihood galling will occur. In an application where the bolt is galling with the internal thread, the bolt is usually presumed to be at fault, because it is the breaking component. Generally, it is the internal thread that is causing the problem instead of the bolt. This is because most bolt threads are smoother than most nut threads. Bolt threads are generally rolled, therefore, their thread flanks are relatively smooth. Internal threads are always cut, producing rougher thread flanks than those of the bolts they are mating with. The reason galling problems are inconsistent is probably due largely to the inconsistencies in the tapping operation. Rougher than normal internal threads may be the result of the use of dull taps or the tapping may have been done at an inappropriately high RPM. Fortunately, stainless steel bolt and nut galling problems do not occur everyday, but when they do it usually creates a customer crisis. Knowledge of why this occurs and how to remedy it can save the supplier much grief and many headaches. Below are the questions that should be asked and the suggestions that should be made immediately when you are confronted with a customer’s complaint about thread galling:

Questions and Suggestions:

1. Are you using the same driver RPM you have used in the past to install these stainless fasteners?

If they say they are driving them faster than in the past or if they say this is a new application, suggest they immediately try slowing the driver RPM and see if the problem goes away. In general, a stainless bolt of a given size should be driven slower than a steel bolt of the same size.

2. Are the bolts and/or internal threads lubricated?

If they say, “no”, suggest they try lubricating the bolts and/or internal threads with one of the lubricants listed above. If this eliminates the galling, you might want to batch lubricate the remainder of the order to eliminate the extra work of applying lubricant at the point of assembly. In applications where galling is a repetitive problem, it is advisable to supply the fasteners with pre-applied lubrication to eliminate future problems

3. Are you using the same grade of stainless steel for the bolts and nuts?

If the answer is “yes”, you can suggest changing one or the other to a different grade. Be sure the suggested grade meets their corrosion needs and changing the material does not cause a procurement problem. When thread galling occurs in stainless steel bolt and nut applications, don’t panic. Try the suggestions listed above. One, or a combination of these, will probably resolve the problem immediately.

This article was published by Greenslade & Company Inc and was reprinted with their permission.

TIE IT DOWN! TIE IT DOWN! TIE IT DOWN!  I say this over and over again all summer long….. Too often I hear about people who put up their canopy, go out to dinner and it’s gone when they get home. Guess what? It wasn’t the neighbor who stole it. Keep in mind that the monsoon season is harder on your canopy than the sun. We recommend that each and every leg of your set-up be well secured!

Using zipties is like drinking too many beers……you need to know the limits! Way too often I see a big guy wrap a 4″ ziptie around some wires and then YANK— putting 250 lbs of bench pressing muscle  into this teeny weeny 18 lb tensile strength ziptie……Guess who wins???  Our zipties provide up to 50% more tensile strength and 15% larger bundle diameters than other products. Their positive-locking teeth, closely and evenly spaced on both sides of the body, provide increased strength and fine adjustment for any bundling need. The raised ridges on the zipties bent tips are designed to provide a secure grip while requiring minimal effort to close. The patented , one-piece injection-molded construction eliminates failure due to parts working loose or breaking off. Smooth, rounded edges make the ties easy to handle and install with cutting hands. BUT, they are not made of Kryptonite!!!! So, know your ratings- know your limits and please don’t ZIP and DRIVE!