|
|
The Newbies Arena Are you new to knife making? Here is all the help you will need. |
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
first heat temp HELP
So I finished my knife and put it in the forge heated to nonmagnetic and then about minute and half more. I went to put in toaster oven to temper to 450 but found that the toaster went to 380 only. I put it through one hour cycle. Do I need to reheat to 1450 or can I just temper another cycle with new oven at 450?
Edit steel 1084 wife informed me she contented 48 seconds after nonmagnetic... guess I lost track of time. I went and got new oven. In process of second heat at 445 to 450 deg. I did quench in oil and wiped off excess. Last edited by remist17; 08-09-2014 at 07:17 PM. |
#2
|
|||
|
|||
You should probably do 2 or 3 more cycles at around 400-450. a one hour cycle at a lower temp won't hurt it at all. as long as you didn't overheat it by leaving it in the forge for another minute and a half. it only really needs to be about 50* past nonmagnetic, but as long as it was hard enough to not be cut by a file right after heat treat then you are probably ok.
|
#3
|
||||
|
||||
You quenched it before tempering right? It wasn't clear in your description. Also you didn't specify what steel you are using.
I usually do 2 x 2 hours in the tempering oven for a total of 4 hours. Tempering at 380?F will produce a higher Rockwell C number than 450?F, but there are trade-offs associated with the lower temperature as well. To answer your question; if your quench went well, you won't need to re-heat to high temperatures. Another tempering at 450?F is your best bet. |
#4
|
|||
|
|||
Check it first. Use a file to see how hard it is. (Be careful, your just looking to see if the file cuts.) If the file cuts easily then you didn't get it hard in the quench. Another test is to take a brass rod, put it in a vice sticking up and press the edge against the brass. Watch for deflection on the edge. Chipping indicates it's too hard, if the edge bends you didn't get it hard enough or over tempered. You can always go up 25 deg on successive temper cycles to take a little more hardness out but once it's gone you can only re-harden once.
You didn't say what steel or type of knife. A small knife made from some steels would be fine at that heat. A 1095 Bowie, not so much. |
#5
|
|||
|
|||
I updated first post but steel is 1084 and I did quench in oil. Right now im 35 min in 446 degree temp. Going for hour and will test with file. I don't have a brass rod handy.
|
#6
|
|||
|
|||
Ok so the second temp at 446f is over. I am not sure what the file is supposed to feel like but when using a file on stock material I feel the file bite the steel I tempered seems the file doesn't bite. It takes off the carbon but no real metal. I think this is what the file should do. Am I right?
|
#7
|
|||
|
|||
A file is just a rough guess, even calibrated files. Personally, I wouldn't have tempered 1084 at 446?. I probably would have started at 400? or even 375? and tested the edge after final grinding. If the blade tests too hard you can always grind any chip out and retemper a little hotter. If you get the blade too soft then the only remedy is to reharden and retemper. It's also going to depend on the use the blade is intended for. If you are making a big chopper then a softer temper is often called for to trade off some of the strength and edge retention for some toughness. If you want to lean a bit more to the edge holding ability I could temper at the lower temps noted above. Your edge geometry is also going to influence your choice.
My favorite test for hardness is driving the edge though some bailing wire or a thin brass rod and checking for any chips, indentations, or rolling over. Doug __________________ If you're not making mistakes then you're not trying hard enough |
#8
|
||||
|
||||
Agree with Doug on this (and occasionally test the same way, just good QC).
Get an extra oven t-meter and double check your tempering heats. Toaster ovens are notorious for inaccurate temps and temp fluctuation without some modifications. Doesn't sound like yours is anywhere close to correct. 1084 @ anything over 400* should file reasonably with a good file. Most makers I know only take their 1084 up to the 375* - 390* range for a general purpose user. Choppers around 420*. Generally "best guessing" will not consistently produce quality results. __________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
#9
|
|||
|
|||
The file test should be done with a small triangle file. Saw it across one place on the edge to see if it cuts into the blade. Ideally it should just skip across the edge. You should also give the blade a little polish before putting it through temper. For carbon steel you can use the temper colors fairly accurately.
If you haven't yet, visit Ray's chat room for newbs tonight. |
#10
|
|||
|
|||
Well I put the knife on the sander 400 grit and its sharp. Cut bunch of stuff and still has edge so im going to sharpen with my stones
|
Tags |
1084, 1095, blade, bowie, brass, carbon, edge, file, first post, forge, harden, heat, heat treat, knife, made, material, metal, post, press, quenched, rod, steel, temper |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Do I really need to heat my quenchant past room temp? | jcoon8283 | The Newbies Arena | 7 | 09-30-2011 09:52 AM |
Low Temp Heat Treating Salts Available | Darren Ellis | General ::: Items and Bargains | 0 | 06-01-2007 01:22 AM |
Heat Treat Furnace to reach Temp? | R. D. Finch | Tool Time | 5 | 03-02-2004 03:23 PM |
YA Heat Treating Question (High Temp Salt?) | Frank J Warner | Ed Caffrey's Workshop | 4 | 02-27-2004 08:30 AM |
critical temp, weld temp, forge temp | YAMAMA | Ed Caffrey's Workshop | 6 | 12-31-2003 11:48 AM |