# How to sharpen twine knife ?



## Farmerbrown2 (Sep 25, 2018)

I run a NH 316 and the twine knife is dull and not cutting twine cleanly so every once and a while knot does not come off of billhook . So I have been reading to sharpen twine knife, well used a new file tonight it did nothing but slide across so what are you guys using to sharpen knife?


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## Coondle (Aug 28, 2013)

I used to use a small oilstone (oil impregnated carborundum) but that is slow. so on a couple of balers I replaced the knife with new. New one lasts a long time, but they need a smear of grease on it to stop rust over the non-hay season taking the edge off. Changeover was longer than sharpening but I knew the knife was good for a long time. If the knife is riveted on, and you choose to replace, grind the rivet heads off and get the little bolts for the knife when buying the knife.

Then I discovered a small diamond-chip encrusted sharpening stone. No it was not my wife's diamond ring but a small rectangular one from the hardware with very fine chips.


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## bbos2 (Mar 20, 2015)

I a lot of the times replace it in yearly maintenance. Once the cutting edge gets roughed up and chipped I replace it. One less thing I have to think about when baling.


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## mike10 (May 29, 2011)

Replace the knife. The new ones bolt on so it will be easier in the future to change. While you have the knife arm out replace the roller on the end of the knife arm. The problem with sharpening the surgical steel knives is you can not get into the corner formed by the reinforcing plate and knife. That is the area where the knife does the cutting. I have seen knives that were sharp along the entire edge except for that corner. If the twine does not cut in the corner the twine will just ride up the rest of the knife and not be cut.


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## kentuckyguy (Apr 13, 2015)

When you replace the roller on the knife arm do you just cut the old one off ? Looks to me like its pressed on.


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## mike10 (May 29, 2011)

On the older balers the end of the knife arm was peened and the roller was considered non replaceable. In the early 70's NH came with a knife arm which had a screw in the end and using an allen wrench you could remove the roller and replace.

What I have done on older balers is take a flat file and using the edge of the file, file around the peened area until the diameter of the end of the knife arm is about the same as the roller inner diameter. Take a screwdriver and pry the washer off, replace the roller, reinstall washer and taking a hammer peen the end of the knife arm again.

When replacing the roller on balers with the screw, take a vice grip on the washer and turn it like you are loosening the screw. This breaks the screw loose and make it easier to get out.


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## Farmerbrown2 (Sep 25, 2018)

I stopped and got new knives today , tonight I will replace them . I just love farming always a new challenge ahead of you always something new to repair and learn about . My dad bought this baler new and this is the first time that the knives will be replaced that I know of.


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## CaseIH84 (Jun 16, 2013)

Just going to throw my two cents in. I agree with everyone up top about replacing knife. Way easier in end to just replace for the money they cost. Also I would make sure the adjustment on the twine scraper that the knife is bolted to is good. Should just lightly rub the bill hook. Also make sure the bill hook does not have any burrs on it. Good luck. The knives are really not bad to replace.


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## Coondle (Aug 28, 2013)

CaseIH84 said:


> Just going to throw my two cents in. I agree with everyone up top about replacing knife. Way easier in end to just replace for the money they cost. Also I would make sure the adjustment on the twine scraper that the knife is bolted to is good. Should just lightly rub the bill hook. Also make sure the bill hook does not have any burrs on it. Good luck. The knives are really not bad to replace.


When checking that the twine scraper (also known as a wiper) on the knife arm contacts the billhook, check the shape of the contact. The leading edge of the scraper should be square-on to the bottom of the billhook as it wipes toward the open end of the billhook. Sometimes the leading edge is lifted and it is only the training edge that contacts the heel of the billhook creating a wedging effect on the twine. Ultimately the scraper will ride over the twine or will damage the twine being wiped off the billhook .

For NH, the knife arm that the scraper is on is malleable and can be bent or gently knocked into the right shape and amount of contact. Only small adjustments until it is right. With some at least of JD there is a set screw holding the scraper plate in position, loosen the set screw and centre scraper plate on the billhook th , with the scraper plate centred on the billhook tighten the set screw. Check the resistance to pulling the scraper across the billhook. Use a spring balance to test and the amount of force should be 10 lbs + or - about 2 to 3 lbs.

Make sure the scraper tail clears the billhook tongue.


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## Westcliffe01 (Feb 16, 2015)

I just sharpened the blade (both sides) on my Hesston 540. It had a groove worn in it on both edges. My blade was soft enough that I could sharpen it with a file (a new sharp smooth file). Rather disappointing, but it worked perfectly afterwards. It was high carbon steel from a test grind I did on one of the sides, one can tell from the sparks. But not hardened properly. I assume it would have lasted a lot longer had it been harder.


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## Farmerbrown2 (Sep 25, 2018)

I got the new knives at NH dealer had a kit in stock bolts included for $15 . Now the funny part, came with two sets of bolts plus instructions I will quote" use long bolts in heavy arm short bolts in standard arm " now how in the world am I suppose to know which ones I have. Plus there where two lock washer that where to small to fit on the bolts. I just love what some smart person thinks some farmer will understand, oh I forgot everybody use's NH service techs so they can stay clean in a cab tractor.


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## mike10 (May 29, 2011)

You will use the short bolts. The heavy duty knotters use the long screws since the knife arm is thicker in that area. Forget the lock washers, the nuts are flanged serrated nuts and will lock tight. I install the bolts so the nuts are against the reinforcing plate above the knife.


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