Expansion Reamers:list5733
Precision holes require precision tools. When machinists need an exact size hole, they want the best tool available to achieve the desired diameter. That’s a job for a reamer. The appropriate amount of stock removal for carbide tipped reamers is typically 2-3 percent of the finished hole size.  This is so the reamer can remove the remaining material to that all important size, and leave a smooth clean finish.  Click here for more on Pre-Ream Hole Sizes. As with all precision tools, instruments, or components, increase costs are explicit in the name, and when costs go up businesses cringe. Enter the expansion reamer.

Expansion reamers are precision tools that can be reused multiple times and are generally used for reaming abrasive material. They are built with slots cut between the flutes and a tapered screw in the head. As the reamer is used and the cutting edges are worn down, the user simply turns the screw to expand the reamer, re-clears it, sharpens it back to its original size and goes right back to work.  Expansion reamers are handy tools that allow the user to keep working with the same reamer multiple times, without having to buy a new reamer.

When using an expansion reamer there are some important things to keep in mind:

  1. Expansion reamers are not meant to be used for multiple sizes. The reamer is set to a specific size and should only be used for that size.
  2. Expansion reamers are not adjustable reamers. The set screw acts as a wedge being turned into the shank of the reamer. As it is turned inward, the steel flutes are bent outward. Once this happens, it cannot be undone. (See chart below)
  3. Once the screw is turned it should never be backed out. Expanding the reamer is a one way street. To bring the reamer back to its intended size, the set screw should be turned, but very minimally (usually about 1/16 to an 1/8 of a turn, and not more than a ¼ of a turn). If the screw is backed out, the tool may not hold its size and the threads could be damaged, preventing further tool expansion.
  4. Expansion reamers are cost effective. Since there is more work involved in making expansion reamers, they are more expensive. However, this higher cost is offset by a longer life span. Using expansion reamers can cut down on the number of tools that will be needed because of the ability to expand the reamer multiple times for reuse.
  5. Expansion reamers are not able to be coated.

Expansion chart for Super Tool’s expansion reamers:

Tool Diameter

Guaranteed Minimum Expansion

5/16”  –  15/32”


½” –   31/32”


1” –  1-1/2”


1-9/16”  –  2-1/2”


For each of the given diameter ranges, Super Tool guarantees that the minimum available expansion of each tool is that specified in the chart. To maximize the number of tool uses, only turn the set screw small amounts and regrind to size. Once the screw is turned, it cannot be backed out. Expansion beyond this given amount is not recommended and may not be possible due to the taper of the screw and the length of the flutes.

Super Tool’s Carbide Tipped expansion reamers have carbide the full length of the flute. This allows for a better finish on the hole.

Super Tool’s standard tolerance on expansion reamers are:

  • Diameters up to 1-1/2” =  +0.0003/-0
  • Diameters over 1-1/2” = +0.0004/-0

Here is a link to Super Tool’s selection of Expansion Reamers.

If you have any questions about Expansion Reamers (or any other cutting tool questions) feel free to leave us a comment here on our blog or fill out the form on Super Tool’s Contact Us Page.

Chadd Brown
Super Tool, Inc.



The flute configuration of a reamer is important.  Selecting the correct configuration helps optimize tool life and hole finish.

Left hand spiral reamers should be selected for through holes.  A through hole has an opening on the other end.  If you put your eye up to the hole, you would be able to see out of the other side of a through hole.  A left hand spiral pushes the chips ahead of the reamer and out the other side of the hole.  This reduces the chances of scarring the work-piece and reduces the chance of damaging the reamer by previously cut chips.  Additionally a left hand spiral helps bridge interruptions such as cross-holes or keyways.  Left hand spirals are excellent for reaming hard materials and typically provide the best size and finish as compared to right hand spiral or straight flutes.

Right hand spiral reamers should be selected for blind holes.  A blind hole is a hole that does not have an opening on the other end.  If you were to put your eye up to the hole, all you would see is darkness.  In a sense, you would be “blind” while looking in the hole.  A right hand spiral pulls the chips towards the back of the reamer.  This helps prevent the chips from getting packed into the bottom of the hole reducing the chance of damaging the reamer and the work-piece by previously cut chips.  Additionally a right hand spiral also helps bridge interruptions such as cross-holes or keyways.  A right hand spiral reamer may cut slightly oversized holes due to the aggressive flute geometry.   They perform very well in highly ductile materials.

Straight fluted reamers are very good general purpose reamers.  They are typically cheaper than left hand or right hand spiral reamers and work best in non-chip forming materials such as cast iron, bronze and free cutting brass.  The preferred hole condition for a straight fluted reamer is a through hole all things being equal but they perform well in blind holes as well due to their non-aggressive geometry.  If all the application parameters are known typically a right hand or left hand spiral reamer will provide superior results in finish and performance then a straight fluted reamer.

For additional information on left hand and right hand spiral reamers while reaming with coolant please see our previous post Reaming with Coolant.

As always if you have any questions about left hand spiral, right hand spiral, or straight fluted reaming (or any other cutting tool questions) feel free to leave us a comment here on our blog or fill out the form on Super Tool’s Contact Us Page.

Bryan Enander
Super Tool, Inc.


Happy New Year!

Posted: 31st December 2014 by brednane1981 in Super Tool


A big thank you to all our customers and fans! 2014 was a great year and we are looking forward to an even better 2015. Always remember that we are here for you and we wish all of you a wonderful, happy, safe, and productive new year! Cheers to 2015!

~Your Super Tool Team


Merry Christmas!

Posted: 24th December 2014 by brednane1981 in Super Tool

From all of us here at Super Tool, we want to wish you a very Merry Christmas. May you all have a wonderful, safe and fun day with family and friends. Thank you for a great year!


The Super Tool Team!


Last week the federal government passed the new fiscal budget bill; a $1.1 trillion plan that was met with mixed reviews (so nothing unusual). While we can all applaud Congress for actually accomplishing something without throwing fists, shouting, or feet dragging – well these were kept at least to a minimum – it’s all the last minute additions that have gotten me upset.

Only the U.S. Congress can pass a bill while adding policies that have nothing to do with the bill, at a lightning speed that often rivals a snail. Along with our new budget – and I say ours because, America, it is our government using our money – comes a list of ridiculous add-ons that most sensible people would raise their eyebrows with an expression of WTF?

First and foremost, the bill loosens the belts of the banks and Wall Street by repealing polices that were enacted in 2010 under Dodd-Frank that aimed to reduce and prevent certain risky financial maneuvers that the banks used to sustain high profits. It also allows the banks to risk the entire U.S. economy – me, you and everyone (and possibly the world) – plunging right back into 2008. And if we follow our history notes, we can see that the banks are 1-0 in recent years at creating recessions when they are allowed to do whatever they want. But do not fear fellow citizen. Big Brother will be there to bail us (the banks and mortgages companies) out should something terrible happen.

The saga continues….

The new budget deal includes a ban on listing the sage grouse (see picture) for being listed as an endangered species so there will be no interference for upcoming oil-drilling projects. It also cuts funding to the EPA (Environmental Protection Agency). Chalk that up next to global warming and you can hear them saying: we care about the environment, but only if it is in the interest of my wallet. The environment has only given us…well everything we have ever had (in the form of raw materials) including Mr. Senator, your money.

The budget bill requires the president and his administration to include white potatoes in a nutrition program for women and children. Moving on…

It prevents the vice president from getting a pay raise. This one I’m ok with. Nobody in government deserves a pay raise.

All-in-all this accomplishment of passing a budget bill on time turned into nothing more than a shopping cart for Congress to dump all their extra crap that they want.

It is because of this that I propose a new way of passing bills in Congress. Each bill (especially budgetary bills) should have to be presented to the public for approval before they take effect and nothing can be added to any bill that does not directly pertain to the bills’ purpose (such as funding the government). And if any politician tries to add something to the bill that has nothing to do with it, they should be fired on the spot. Come on America! Start making Congress actually work for us.  I welcome your comments.

Chadd Brown
Super Tool, Inc. 




With Election Day behind us, we get to stop hearing all the political ads and commercials that plague our TVs and radio stations with the same dribble that seems to be repeated every time elections come around. Signs for candidates get pulled from our front lawns and candidate supporters stop crowding our street corners cheering vote for this, that or anything else.

But one thing that does not seem to be going away is the push for the legalization of marijuana. In fact, it seems the opposite is happening: more and more people are speaking up in favor of it, which is leaving many state governments in a bit of jam. Currently there are 23 states that have legalized marijuana for medicinal purposes only.  Several states –Colorado and Washington-had already fully legalized it (both medicinally and recreationally) and this year’s election added two more states-Oregon and Alaska-to fully legal marijuana status (Washington, D.C. also approved legal recreational use of pot, however this is subject to Congressional review as D.C. is only a territory and not a state). Other states, such as Florida, tried to pass medicinal marijuana laws, but failed to acquire enough votes to pass any legislation.

So the country, while still divided on the issues of medicinal and/or recreational marijuana, seems to be progressing forward. On top of all the “legal for medicinal-legal for recreational” debating among the states, the federal government still classifies it as an illegal substance. This is why the insurance companies will not cover the costs for medicinal marijuana: It’s not FDA approved!

This dilemma over the legalization of marijuana is leaving business owners scratching their heads. In states where marijuana is already legalized business owners are having a hard time because they do not know how to address the issue. Questions arise over how to enforce, regulate and/or prevent marijuana policies.

If the federal government considers it an illegal substance, and insurance companies do not cover it, then is the business with its own health plan for employees required to cover it? Is the business still considered a “drug-free” work place if an employee has a prescription from their doctor to use a drug that the state says is ok but the feds say otherwise? If a company has a policy against the use of cannabis, is it possible to terminate people if they test positive for it even though they may have used it a home and not at work? Is the company legally responsible if something happens on the job if the employee is high? Can a company deny the use of marijuana at work even if it is medically prescribed? Are random drug tests considered discrimination under the Disabilities Act?

This is a small list of questions that need to be addressed. There is little doubt that marijuana has its uses for medicinal purposes. It would also help alleviate the over-crowding of the prison system, create more jobs, increase tax revenue, lower the cost police officers and governments have to spend on combating its use, and help cancer patients with treatments and appetite regulation. Add the fact that our society (and government) allows for much more harmful substances such as cigarettes and alcohol to have free range in the market just increases the amount of contradictions that are piling on to the debate.

But no one is addressing how this will affect other businesses and their ability to manage the use of marijuana by its employees. We have proven that prohibition was a failure and went back to allowing people to buy and sell alcohol. This wasn’t a problem for businesses: no drinking on the job. Cigarettes are allowed to be smoked on breaks and sometimes even in certain parts of the buildings. But pot? The shoulders get shrugged and hands thrown in the air with mindset of “I have no idea.” Meanwhile, the varying levels of our government are grazing on the same grass on opposite sides of the fence.

So business owners and managers, I pose the question to you: How do you feel about legalizing pot and what are your concerns? If you are in a state where marijuana is legal for any reason, how are you dealing with these issues?

Chadd Brown
Super Tool, Inc.


keep-calm-and-ask-me-questionsTwo years ago, we began a research project to expand our horizons and to find new ways to reach out to our customers, both new and long standing. Through our brainstorming we looked at and investigated the various ways other businesses were reaching out their customers and found, surprisingly, that in our industry of cutting tool manufacturing not much more than the traditional methods of consumer interaction was being employed. This presented a challenge to us, as there were not many templates or outlines that could be studied. It was not about trying to copy someone’s work, but rather looking at what Business X did and comparing it to what Business Y did and then trying to improve and tailor it to our own styles.

This led us to social media. We begin the process over and again, we found very little. Sure, we found that big companies had their social media platforms and interactive websites. They were beautifully designed and elaborate, but something that a small business like us would find difficult to relate to. So we decided that if we wanted to try something new, we would have to blaze our own trail.

We wanted to be able to provide a forum to open up new avenues of communication that anyone person, not just our customers, could talk to us. We wanted to be available to answer technical questions, offer helpful tips for our cutting tools and the projects you are working on, and provide insight into the status of manufacturing in our country and the state of the manufacturing industry. We want and encourage students to ask questions and use our knowledge. It wasn’t just about putting our name out there, but also about giving back to the community through education and assistance. We wanted to do our part to help manufacturing continue to grow.

I am proud to say that after a strong two year start, we have done exactly that. We created a blog site (http://blog.supertoolinc.com/) with a large and growing collection of topics from tool performance to the power that manufacturing can provide to our economy.  We have also established a presence on the top social media platforms – Facebook, Twitter, and LinkIn – to allow for even greater reach.

Now we are here to ask you: What do you want to hear from us? What can we do to help you? If you or a friend or colleague is having trouble with tooling or has a question about tooling manufacturing, let us try and help you. Our blogs are meant to provide you with resources to improve your manufacturing, lower your costs, and increase tool life. So what’s on your mind?

Chadd Brown
Super Tool, Inc.