| Possible Causes | Possible Solutions |
| Unequal Chamfers | Regrind the reamer with equal chamfer heights. |
| Incorrect Margins | Regrind the reamer with narrower margins for reaming higher tensile materials. |
| Excessive Spindle Runout | Use bushings that are .0002″/.0003″ over the reamer’s diameter. |
| Chatter | Increase feed and reduce the speed rate. |
| Use power feed unless the material being reamed is hard. | |
| Use a spiral fluted reamer. | |
| Grind a secondary lead angle directly behind the 45° chamfer. | |
| Insufficient Cutting Action | Use a reamer with positive radial rake to reduce the cutting pressure. This may produce slightly larger diameter holes. |
Another common reaming problem is the shape of the reamed hole including Oversized Holes, Tapered Holes, and Bell Mouth Holes. Possible causes include misalignment and using the incorrect feed and/or speed. Below is a table with possible solutions for each of the possible causes of Oversized Holes, Tapered Holes, and Bell Mouth Holes:
| Possible Causes | Possible Solutions |
| Misalignment | Check fixturing & setup for possible causes; use floating tool holder if necessary. Consider using precision bushings or piloted reamers. |
| Incorrect feed and/or speed rate | Verify correct feeds and speeds. |
| See previous post Reaming Speeds and Feeds. |
Another common reaming problem is Excessive Tool Wear. Possible causes include improper amount of stock removal, excessive reaming pressure, and misalignment. Below is a table with possible solutions for each of the possible causes of Excessive Tool Wear:
| Possible Causes | Possible Solutions |
| Improper Amount of Stock Removal | Change pre-ream hole size to leave 2 to 3% of tool diameter. See previous post Pre-Ream Hole Size. |
| Excessive Reaming Pressure | Decrease feed rate. See previous post Reaming Speeds and Feeds. |
| Change pre-ream hole size to leave 2 to 3% of tool diameter. See previous post Pre-Ream Hole Size. | |
| Misalignment | Check fixturing & setup for possible causes; use floating tool holder if necessary. Consider using precision bushings or piloted reamers. |
Another common reaming problem is Crooked Holes. The most likely culprit here is the drill walking or incorrect sharpening of the reamer. Below is a table with solutions for the possible causes of Crooked Holes:
| Possible Causes | Possible Solutions |
| Drill Walking | Correct the drilling operation. A reamer will follow the drilled hole. |
| Incorrect sharpening of the reamer | Increase the 90° included chamfer angle to 120° – 180° |
Another common reaming problem is Tool Breakage. Below is a table with solutions for the possible causes of Tool Breakage:
| Possible Causes | Possible Solutions |
| Excessive Reaming Pressure | Decrease feed rate. See previous post Reaming Speeds and Feeds. |
| Change pre-ream hole size to leave 2 to 3% of tool diameter. See previous post Pre-Ream Hole Size. | |
| Misalignment | Check fixturing & setup for possible causes; use floating tool holder if necessary. Consider using precision bushings or piloted reamers. |
I’ve addressed the most common problems encountered while reaming but this post by no means addresses them all. If you are having issues reaming please leave us a comment here or drop us a line on Super Tool’s Contact Us page. We are happy to help.
Bryan Enander
Super Tool, Inc.
941-751-9677
i have doubt regarding how to solution to be seen ocular line mark issue ,shall i increased rpm or increased feed please revert back as soon as possible
Can you provide more detail on the application? I’m not sure what you are asking.
Thanks,
Bryan
HI
I have a left hand spiral flute Reamer and i want to know that i only have a hand drill so what torque setting should my dewalt be set to. i have the problem that bits start coming of the side of the reamer then it is no use to me and it is expensive to replace. i am drilling through hole.
i am doing the drilling in forward gear is that correct.
thanks for your help
Even though we recommend using our tools in precision equipment all of the same parameters would still hold true in a hand drill. Shoot for 2-3% stock removal I would aim more toward the low side with a hand drill and try to mimic the speeds and feeds for the appropriate material. Torque should be set at a maximum and no stopping and starting or reversing in the hole. That is probably what is causing the chipping. Here is a link to our reaming speeds and feeds chart: http://www.supertoolinc.com/uploads/ReamingFeedsandSpeeds.pdf.
hello sir,
I am student of last year mechanical engineering. i want to know about which types of inspection done on the reamer tool and which instruments are use for inspection. this is helpful for my final year project. please help me regarding this.
Hope for your positive reply..
Hey Nikunj,
Sorry for getting back to you so late. As part of our quality policy, we require a first piece inspection on every job that goes through our shop. This allows us to make sure that all our tools are being made to spec and maintain our output of quality tools. This process also allows us to address any problems that may occur during each step of production, and, if a problem is discovered, we can catch it on the first piece and correct it, without having to scrap out an entire job. All tools go through a final complete inspection before they are shipped out or placed into inventory. This is applied to every job that is run through our shop, regardless of what particular tool it is.
As for reamers specifically, we use a variety of measuring tools during the inspection process. Below is a basic breakdown of what tool we use to measure the reamers’ specs:
Diameter and Back Taper – Micrometers
Core (flute root), Overall Length, Length of Cut/Flute – Calipers
Circular Margin and Axial Rake – Optical Comparators
Spiral (if any) – Machine Settings
I hope this helps, and if you have any other questions please feel free to ask.
Thanks
Chadd Brown
Super Tool, Inc.
Hello Sir,
We are machining Cyl. Head as below detailed ,
Component Material – Gray Cast Iron
Hardness – 180 to 220 BHN
Now, we are facing valve guide (Parent bore operation) suddenly oversize issue.
When we do tool change 1st component is ok and up to 10 comps are ok, but it suddenly shows oversize by 30 to 50 micron and if we continued same tool then again we got ok components.
Tool Details are below –
Tool Make – MAPAL (Valve seat and guide cobintion tool)
Reamer – Dia.12 Solid carbide with HSF head
Machine Details –
Make – Makino
Type – HMC
Request to Pl guide for same.
Rgds,Vivek
Hi Vivek,
The MAPAL tool is a specialty type of item. It would be best to check with who you purchased this tool from but it sounds like maybe the tools is not securely held in place at first and is moving slightly after a little bit of use and then finally settles into place. Check the setup of the tool; be sure it is securely locked in place and also check with the manufacturer or whoever you bought the tool from for their recommendations.
Good day sir,
I am having a reaming issue where the profile (circularity) of the hole comes out pinched (oval in shape, squeezed on the sides). I have checked the pre-reamer, finish reamer and tooling. I have found nothing out of the ordinary. I have messed around with feeds and speeds but am in no way confident I’m doing the right thing with them. I am machining a valve guide on a cylinder head, cast aluminum alloy with 8-13% silicon content.
Do you have any suggestions on how to fix a profile (circularity) issue such as this?
Usually speeds and feeds or stock removal are the problem. Since you are using a pre ream you most likely aren’t leaving enough material in the hole for the reamer to engage properly. The hole should be 97%-98% of the finished hole diameter. So, if you want your finished hole to be 1.000″ your pre ream hole size should be .97″ – .98″ in diameter. Just take your finished hole size and multiply by .97 to get the low end and .98 to get the high end.
Also, here is a link to our speeds and feeds chart: http://www.supertoolinc.com/uploads/ReamingFeedsandSpeeds.pdf
Thanks,
Bryan