FAQs and Troubleshooting

Should the following answers not give you all the information you need, feel free to click the "Live Chat" icon to the right to speak with a live service representative, call or use the contact link at the top.


How do I order Invert-A-Bolt™ Products?

Ordering is easy! Call the customer support line at 877-462-BOLT (2658) or shop anytime using our online store. We accept cash, Visa, MasterCard, AMEX, and terms (purchase order with approved credit).  In addition, some products are available through Amazon.com.  Search at Amazon.com for the part number in which you are ordering.

When can I expect to receive the product I ordered?

Many of the Invert-A-Bolt™ fasteners and insertion tools are stocked. Universal Common Modular fixtures and tombstones are made to order and will take several weeks to ship. Once your products are shipped, you will receive a tracking number by e-mail. For more specific information regarding your order please call customer service toll free at 877-462-BOLT.

Click Here For Shipping Policy

Who else uses these products?

Our market exposure is greatest in the aerospace industry, but we have also made sales to the commercial OEM industry, medical, semi-conductor & weapons industry. As our market exposure increases we expect to service manufactures of all types in many industries since our captive fasteners and modular fixtures can be applied to a multitude of manufacturing processes.

Our customer list includes: Boeing, Bombardier, Embraer, Cessna, General Electric, GKN, Heroux-Devtek, Nellis AFB, Nike, Palmetto State Armory, Raytheon, Sikorsky Aircraft, TECT, United Space Alliance, Warner-Robbins AFB, as well as many other companies in the U.S. and throughout the world. In short, these products are suited for manufacturers in many diverse industries.

What about discontinued products?

From time to time we analyze our products for acceptance in the marketplace and whether they are meeting their sales targets.  We regularly cull our market offerings to only those products that are succeeding in meeting broad customer demand.  Where it is not warranted to continue production, we cease manufacturing the product. We recognize this as a possible hardship to current users of that product, so we don't completely shut-off the ability to obtain the product.  Rather, we ask for minimum quantity purchases with pricing that is consistent with the higher costs incurred when the products are made.  Bottom line: we're not going to leave you high and dry!   If you purchased a product from us, you can get it again.

What is your return policy?

Click Here For Return Policy


What about performance of inverted bolts to clamps? How do they save me money?

There are several factors which affect overall performance when considering a comparison between clamps and Invert-A-Bolt™ fasteners: 

a) Typically a machine operator spends a great deal of time searching for the right length bolts (for the heel and stud of the clamp) when initially setting up a job run. (Another common problem occurs when a NC program counter-bores a hole to a certain depth requiring a "right length" bolt to accommodate the hole.) The machine operator may actually cut bolts or modify the mill fixture if the right length bolts cannot be located. This time can be multiplied if a double-sided part is being milled and thus two sets of bolts are required. Often the bolts are not kept with the mill fixture and so, for every job run, this process (and wasted time and effort) is repeated.

b) Various time and materials issues concerning the clamp as an obstruction to the machining process. (NC Programmer - must program around the clamps and find efficient machining sequences while considering clamp changes, Machine operator - must move clamps during machining operations. Two different sets of bolts may be required for the clamp changes when considering double sided parts). The probability of hitting clamps and causing damage to the part, endmill, and/or machine tool is high.

c) Additional material required on the mill fixture to position clamps. Typically clamps are 2" to 4" long and the mill fixture is increased in size to accommodate this stickout away from the part stock.

d) If the part configuration requires bolting from the backside, no special mill fixtures (bridge fixtures, double sub-plate fixtures, etc.) are required.

Other thoughts:
The Invert-A-Bolt™ fastener is not necessarily ideal for every machining application. Ideally, it can be applied to parts that can be "picture framed" and tooling tabs can be used to hold the part during machining. Some of the highlights of the product are:

a) The inverted bolt is maintained in a "housing" which is secured in the mill fixture. The housing is threaded and thus allows for easily replacing the Invert-A-Bolt™ assembly should it become damaged. This also allows for the bolts to always be available at each production run (or whenever it is used). There is no need for a machine operator to find right size bolts.

b) The bolt contained in the Invert-A-Bolt™ assembly sticks up into the part a short distance. Only the stud part of the bolt sticks up into the part. This allows for a minimal obstruction surface for each Invert-A-Bolt™ Fastener. This provides a much smaller footprint during the machining process and requires no changes. In fact, the stud can also be recessed completely during the process which could allow for the tooling tab to be milled completely off during the machining process.

c) No additional stock is required on the mill fixture outside the part stock limits.

d) Because only the stud sticks up into the part (the "footprint" of the Invert-A-Bolt fastener is the diameter of the stud), part stock requirements can be reduced.

e) All machining operations required to make the mill fixture (holding the Invert-A-Bolt™ fasteners) are performed from one side. There is no requirement to flip the mill fixture over to prepare or install the Invert-A-Bolt™ products. This means all preparation is from the front side of the mill fixture.

f) Multi-purpose holes (ZipBushings), XZertZ, Fasteners and modular components can be used to create an Invert-A-Bolt™ Common Modular Fixture allowing for a mill fixture that can accommodate both conventional clamping as well as Invert-A-Bolt™ products. A very flexible and efficient mill fixture concept can be designed since all the Invert-A-Bolt products are installed from the front of the mill fixture and use a threaded housing.

g) By using Invert-A-Bolt™ products, the need for helical inserts in an aluminum mill fixture is eliminated.

h) Invert-A-Bolt™ products are being used in production environments at many manufacturers across the United States. The products are well received and being used successfully in many part/mill fixture applications/configurations.

I'm having problems bringing the stud up into the part. What can I do?

Be certain that the chamfer on the "receiving" side is being machined. Either add the chamfer (if left out) or increase its size to enhance the ability of the stud to align itself with the receiving hole, thus alleviating the problem. See the installation and operating instructions page for additional information.

I'm having problems with studs sticking up above the housing. What can I do?

This condition indicates that the cover is worn out and requires replacement. Call us today to find out how.

Why Universal Fixturing?

For many milling applications and manufacturing solutions, using universal fixturing is a very efficient use of resources and an excellent holding solution for many manufactured parts.  Here are some of the advantages for using universal fixturing as opposed to conventional fixturing: Reduce overall tooling costs by:  

  • Eliminating dedicated fixturing and creating a "standard" tooling plate
  • Eliminating tool design and tool build for dedicated mill-fixtures
  • The tool once in service is used perpetually for all applicable part configurations. This has several advantages:
    • The tool is not stored "somewhere out there", its always in use and doesn't require additional storage area(s) to be utilized. (Not to mention, identification, indexing, and other inventory considerations.)
    • Eliminates maintenance of dedicated mill-fixtures
    • Eliminates perpetual capital investment in dedicated fixturing
    • Tool cost can be spread over many parts to reduce "one-time" tooling expense
    • Eliminates load and unload time for dedicated mill fixtures
  • Establishing standardized work holding techniques.
  • Eliminating duplicate fixturing

In addition, a universal fixture (purchased or created) using Invert-A-Bolt™ components offers the following:

  • The unique benefits of Invert-A-Bolt™ products.
  • The use of other modular fixturing components together with Invert-A-Bolt™ products.


Why is it necessary to buy an insertion tool?

Due to the unique design of the Invert-A-Bolt™ outer housing, it would be rather difficult to install the housing completely without the insertion tool designed just for that purpose (flush mount application).

Why is it necessary to buy the Pro-1 Torque-Limiting Pneumatic Wrench?

Many of the common problems that users encounter can be reduced or eliminated by the use of the Pro-1 pneumatic wrench. The Pro-1 has a low torque range from 9-81 ft. lbs. and is conveniently controlled via a 4 step knob. The difference between a Pro-1 and a regular torque wrench is that force is applied vertically instead of horizontally preventing stripped holes. 

What is the best way to create the hole that accepts Invert-A-Bolt™ fasteners?

Thread milling is probably the fastest way to thread the holes if there are a great number of them. Otherwise, a tap is adequate for producing the thread. Recommendations and step-by-step instructions can be obtained in the installation guides. For applications in which excessive vibration is an issue, a Spiralock® tap should be used to create the receiving side hole used to accept the stud.

Should I torque the fasteners or precision locators when installing or using them?

Yes! The torque wrench or pneumatic wrench should be set to a maximum torque of 35 ft-lbs. for the installation of the housing into the plate. Higher settings may result in damage to the insertion tool. Torque settings for pulling the stud into the mating material will vary based upon the Invert-A-Bolt product being used. In general a setting of 30 ft-lbs. should be adequate. Higher settings may be used with the 1/2" & 5/8" diameter fasteners.  We highly recommend the use of a torque limiting wrench (PRO-1) to install the fasteners, as well as during use. We offer an excellent product to provide proper torquing for both installation and use of the fasteners. 

What if I use too much torque?

Unnecessarily using the maximum torque, or exceeding it, can cause fasteners to seize and lock into the material being machined. Excessive torque in soft metals may also result in stripping of the threads in the receiving side hole. A Pro-1 Torque-Limiting Pneumatic Impact Wrench can mitigate this risk by giving you control of the amount of torque used. For example, it would not be advised to use the maximum torque limit of a 3/8" Invert-A-Bolt to hold aluminum material. The stock and bolt size must be taken into consideration. If you are unsure of how much torque to use or have experienced an Invert-A-Bolt seizing up, please give us a call and we are happy to share our best insight. You can also refer to the applicable fastener found on the shopping page to obtain exact information. 

I'm having problems stripping the hex head of the stud. What am I doing wrong?

See above question about maximum torque values. Typically this problems occurs when a pneumatic wrench is used at a torque level set higher than the recommended level. To alleviate the problem, consider setting the torque level lower, use a ratchet type wrench when engaging the product with the part, or use a ball-end hex wrench. Note, a refurbishment kit can be purchased to replace the internal components of the fastener, including the stripped stud.

I'm having trouble screwing the fastener into the plate. What can I do?

Double check the counter-bore size. It should correspond to the minor diameter of the outer thread of the housing. This hole size is critical to the successful installation of the fastener. Also insure that the hole has been prepared to the installation and operating instructions. Be sure to use the proper size go/no-go plug gages to check the hole.

The stud is vibrating loose when in use. What can I do?

Make sure that you are using enough torque when screwing in the stud. Recommended settings range from 30 ft-lbs. and up. Also, consider the material being machined and the fastener being used. Harder materials will require higher torques and the smaller stud fasteners won't be able to be torqued as high due to their hex size. Also, try using a Spiralock® tap which incorporates proprietary thread forms to improve resistance to vibration.

I'm having trouble with the stud locking in the down position. What's wrong?

The stud has limited ability to move around, thus for best results drive the stud in and out of the fastener in an upright position as much as possible. If this occurs, don't force it! Just reverse the stud and start over, driving the stud straight in.


Is maintenance required for Invert-A-Bolt™ fasteners?

Maintenance is generally limited to replacement of the stud when damaged or the hex is stripped out. However, all the internal components of the fastener can be easily replaced either individually or with a refurbishment kit. Also, to improve the life of the hex in the stud, use a ball-end hex wrench. If using coolant, slot the fixture below the fasteners to enable the "flow through" design of the fastener. Additionally, there will be lower maintenance when using one of the fasteners that incorporate the top seal used to eliminate debris entering the fastener.

What happens if a product fails?

There is a full 90-day warranty on Invert-A-Bolt™ fasteners and insertion tools. The company will replace any defective part due to defects in the material or workmanship of the product. If the warranty period has expired, the product can be refurbished.

I'm having problems with metal chips getting into the housing.  What can I do?

Typically this situation occurs in vertical machining when the Invert-A-Bolt™ fastener is in the "dis-engaged" position and is not being used. The flow of coolant and chips in this situation may result in accumulations inside the housing. This is a common hazard to vertical machining applications in which the Invert-A-Bolt™ fastener is not dedicated in its use. Some customers opt to plug most of the holes with a plastic plug, leaving only the fasteners in use to remain in the table. Please see the accessories page for information on the available plugs or caps that can be used with fasteners.

What is the Refurbishment Kit?

Refurbishment kits consist of all the components that are internal to the fastener. Additionally, the covers and studs can be purchased individually (quantities >100) if a complete refurbishment kit is unnecessary. We do not provide a replacement for the housing.

What about cross threading? Is that an issue for the fasteners?

No, the fasteners will not cross thread while in use. Their design prevents that from happening. The engaging stud releases prior to entry to the receiving thread.

What is the difference between -021 and -061 fasteners from the 001 type?

In late 2010, the AA02-015-001c "classic" fastener, was redesigned so that it would require LESS maintenance. Ultimately many of the changes were then duplicated in several of the other fastener products. Please check out the following list of changes that you can expect when comparing the old with the new:

  • Look for a part number change. The newer designs are AA02-XXX-021's, AA02-XXX-031, AA03-XXX-021's or AA03-XXX-061's.
  • From the outside the fastener looks very similar. It will incorporate the same OD thread on the housing and stud. The fastener will fit in the same thickness plate as previously used.
  • The newer products incorporate (4) insertion holes in the top in a "crow's foot" pattern.
  • A new, (4) pin spanner wrench, has been introduced, to match the holes in the top of the upgraded fasteners. The new insertion tools can only be used for one type fastener now.
  • AA02-004-004 insertion tools are used for AA02 products, AA03-004-004 insertion tools are used for AA03/AA06/PL03 products. Greater life and better handling can be expected with the (4) pin spanner wrenches due to a re-design that incorporates replaceable tips. To drive older fasteners, just screw down the center pin of the insertion tool.
  • We highly recommend the use of a torque limiting wrench for installation of all the fasteners. This wrench will only apply a certain amount of force, which when combined with the new insertion tools, will eliminate breakage of the insertion tool tips as well as prevent damage to the drive holes in the face of the fastener. Check out the PRO-1 Pneumatic Torque Limiting Wrench, our offering for this application.
  • The AA03-002-002 insertion tool is now obsolete and no longer manufactured.
  • The fastener is no longer held together with a retaining ring in the base of the product. Rather it is pressed together, using an arbor press or similar.
  • There are slots in the base of the product, in the cover, which promote the flow of debris and fluids out the bottom. By using a slotted fixture in conjunction with coolant, the fasteners will “self-clean”, reducing the workload required for maintenance due to debris.
  • Assembly/disassembly type tools are available that will facilitate the easy refurbishment of the fasteners. Assembly is much simpler. Dis-Assembly is a little more difficult. For more information, see the Refurbishment Instruction Sheets for the specifics.
  • For the AA02-XXX-021, AA02-XXX-031 & AA03-XXX-021 fasteners, look for a change in the stick-out of the stud from .45" to .38".
  • For the AA03-150-021 & AA03-150-061 fasteners (5/8"-11), the 1/4" hex has been changed to 5/16" which boosts the torque capability from 64 ft. lbs. to 100 ft. lbs. This should be especially helpful when holding titanium or harder materials that require more torque.
  • Look for a change to the chamfer size on the receiving (Part) side hole. For more specifics, see the applicable installation instruction sheets.
  • With the acceptance and greater use of Precision Locators, a new class of fasteners, the AA03-XXX-061s have been created to fit in the same hole as the PL03-015-001 Precision Locator. That means that they are designed to be used in 1.50" or thicker plates. The stick-out of the studs for the -061 type fasteners is greater, at .600". Both 1/2" and 5/8" are available options in this size.


Why do some of the products come shiny and others are brownish in color?

Many of our products are some variation of stainless steel, which after machining are generally shiny in appearance. Depending upon which product it is, there may be secondary processes applied to improve different operating characteristics of the product. Sometimes these secondary processes cause some color change to the materials. When you see that you can conclude that we have IMPROVED the product with these processes and if they do cause coloration changes, we have determined that the benefit outweighs the difference in appearance. 

What materials and hardness are the Invert-A-Bolt™ Fasteners/Precision Locators made from?

This information is included in the applicable catalog pages. See also the following FAQ.

Have the products had any failure tests performed?

Yes. Quite a while ago, we failure tested the AA02-001-001, AA02-010-001, and AA03-010-001 fasteners. Although the fasteners have been re-designed and updated since then, this information can be helpful in determining relative holding power. We have not tested recent versions of the fasteners since their capabilities have been proved through literally hundreds of thousands of use in multiple industries all over the world.  They are very similar to other fasteners of similar size and quite adequate for many holding situations.  The information provided here is strictly for reference.

Following is an excerpt from the AA03-010-001 test report:  

"Six fasteners of the above part number were received for tensile and shear testing (three each). Due to the specialized nature of the fastener, it was necessary to produce a unique test fixture to allow for proper testing. The test fixture was designed such that the same fixture could be used to perform both the tensile and shear test.
The test results for both tensile and shear testing follow. In all cases the tensile failures occurred in the hex recess area of the 1/2-13 threaded end as would be expected. the shear failures occurred partially in the hex recess area. Of special note - the shear failures were not typical of shear failures in standard fasteners. Instead of the normal abrupt shearing action, these fasteners deform and slowly tear. For purposes of this report, shear failure was defined as the initial point of macro deformation."  

AA03-010-001 Tensile Test
Serial # Width Dia. or Gauge Area (sq.in.) Yield (lbs) Yield (psi) Ultimate (lbs) Ultimate (psi) Elong (%) Red. of Area (%) Type
1   1/2"-13 .1419     14,762 104,030*      
2   1/2"-13 .1419     15,485 109,120*      
3   1/2"-13 .1419     12,433** 87,610*      

* The psi (stress) is calculated from the thread stress area (.1419); however, this number is not accurate because it is based on a solid cross-section and this part has a hex recess which subtracts from the cross-sectional area.
** The third test result was not valid because the 1/2"-13 screw was not properly engaged into the test fixture.

A03-010-001 Single Shear Test
Serial Number Diameter Shear (lbs) Shear (psi)
1S 1/2"-13 13,243 93,330
2S 1/2"-13 12,928 91,110
3S 1/2"-13 11,256 79,330

Following is the test data for the AA02-001-001 (1" dia. housing x .801" length, 1/2"-13 Stud) product:

AA02-001-001 Tensile Test AA02-001-001 Shear Test
S/N Dia. or Gauge Area (sq.in.) Ultimate (lbs)* Ultimate (psi) S/N Dia. or Gauge Area (sq.in.) Ultimate (lbs) Ultimate (psi)
1 1/2"-13 .0928 10,363 111,670 1 1/2"-13 .0928 9,874 106,400
2 1/2"-13 .0928 11,413 122,980 2 1/2"-13 .0928 11,878 128,000
3 1/2"-13 .0928 10,957 118,060 3 1/2"-13 .0928 11,173 120,400

*Note: All failures occurred at the housing. Following is the test data for the AA02-010-001 (1" dia. housing x 1.150" length, 1/2"-13 Stud) product:

AA02-010-001 Tensile Test AA02-010-001 Shear Test
S/N Dia. or Gauge Area (sq.in.) Ultimate (lbs)* Ultimate (psi) S/N Dia. or Gauge Area (sq.in.) Ultimate (lbs) Ultimate (psi)
1 1/2"-13 .0928 13,354 143,900 1 1/2"-13 .0928 6,080* 65,520
2 1/2"-13 .0928 14,633 157,670 2 1/2"-13 .0928 11,314 121,920
3 1/2"-13 .0928 15,386 165,790 3 1/2"-13 .0928 12,266 132,180

*Note: Housing was backed off from screw.


Should I use a locking solution to ensure the housing doesn't move due to vibrations, etc?

Using a locking solution (like Loctite®) to secure the Invert-A-Bolt™ housing is not recommended. Light duty thread locker can be used, but we cannot be responsible for insertion tool breakage as a result. Care should be taken when applying locking compounds of any type. This practice defeats the unique characteristic of the Invert-A-Bolt™ product to be easily maintenanced from the top of the fixture or completely replaced, if need be. Most of the fasteners are designed with a left hand thread so that movement will be away from the part.

What can I do to improve performance of my Precision Locator?

Be certain to re-apply anti-seize compound to the locating portion of the stud as required. In addition, consider leaving the stud in the "up" position prior to loading. This allows helps "finding" the hole with the stud. Also, bring up the Precision Locator stud FIRST, prior to the other fasteners.