Need help with metric bolts sizes and grades

[kco]

I've searched TBN and the internet and am unable to determine what the markings mean on bolts on my Kioti DK35.

Bolts holding in loader pivot pins in place are 10 mm in diameter and have:

DD
7T i.e. "DD" over "7T"

Large bolts mounting the loader to the frame are 14 mm diameter and have the marking:

OM
10.9 i.e. "OM" over "10.9" over and underline

The smaller loader mounting bolts are 12 mm in diameter and have the marking:

DS
9 i.e. "DS" over "9"


Large bolts mounting the ROPS base to the frame (diam. unknown (approx 20 mm?)):

7T
DS i.e. "7T" over "DS"

The large main bolt that the foldable ROPS swivels on (diam. unknown (approx. 25 mm?)):

10.9
DH i.e. "10.9" over underline over "DH"

Does anyone know what these markings mean? I'm confused because the torque chart that came with the loader just lists torques for ISO Classes 8.8, 10.7 and 12.9.

 

[BillP603]

I know the 10.9 is a grade marking, like Grade 5 Grade 8 is for standard bolts. The double letter is a manufactures mark required by the DIN standards. Not sure on the T, I believe it may mean tempered. Here are a couple of links to technical information that I have used in the past:

Technical Information | Fuller Metric Parts Ltd.

Frequently Asked Questions on Bolting Matters

Hardware is one of those things that there "are so many standards to choose from"...

 

[grsthegreat]

i was in the same quandry..... the torque guide lists the bolt thickness also as i remember. i used the thickness of the bolt to determine the torque

 

[kco]

I did a bit more digging and found bolt standards to be quite confusing.

The markings such as 7T (other common ones are 4T and 9T) are Japanese Industrial Standard (JIS) grades and indicate 1/10 of the nominal tensile strength in kgf/mm2.

Metric grades such as 8.8 indicates a nominal (minimum) tensile ultimate strength of 800 MPa and nominal (minimum) yield strength of .8 times tensile ultimate strength or 0.8(800) = 640 MPa.

A metric 10.9 bolt is medium carbon steel, quenched and tempered while a 10.9 (underlined 10.9) is a low carbon boron steel, quenched and tempered.

What is very confusing with my Kioti DK35 is they use a different bolts for the loader mount. The front four main bolts are 14mm diameter, DIN 10.9 bolts that have a 22 mm head and are torqued at 164 lbf-ft. The back four main bolts are 14mm diameter, JIS, 9T bolts with a 19mm head and should be torqued at 133 lbf-ft.

If the front four bolts where ANSI/ISO instead of DIN they all would be the same except the head would be 21 mm instead of DIN's 22 mm.

I torqued the JIS bolts incorrectly because I assumed all bolts were the same type (DIN) and that the Kioti loader parts diagram had the wrong diameters. The four front bolts had 22mm heads and the four back ones 19mm heads. So (incorrectly sticking with the DIN type) I assumed the back ones were 12mm diameter. I now think they are 14mm diameter bolts (with the JIS 19mm head) as labelled in the parts list.

I've attached a Metric Bolt Head/Wrench Size table.

 

[grsthegreat]

I did a bit more digging and found bolt standards to be quite confusing.

The markings such as 7T (other common ones are 4T and 9T) are Japanese Industrial Standard (JIS) grades and indicate 1/10 of the nominal tensile strength in kgf/mm2.

Metric grades such as 8.8 indicates a nominal (minimum) tensile ultimate strength of 800 MPa and nominal (minimum) yield strength of .8 times tensile ultimate strength or 0.8(800) = 640 MPa.

A metric 10.9 bolt is medium carbon steel, quenched and tempered while a 10.9 (underlined 10.9) is a low carbon boron steel, quenched and tempered.

What is very confusing with my Kioti DK35 is they use a different bolts for the loader mount. The front four main bolts are 14mm diameter, DIN 10.9 bolts that have a 22 mm head and are torqued at 164 lbf-ft. The back four main bolts are 14mm diameter, JIS, 9T bolts with a 19mm head and should be torqued at 133 lbf-ft.

If the front four bolts where ANSI/ISO instead of DIN they all would be the same except the head would be 21 mm instead of DIN's 22 mm.

I torqued the JIS bolts incorrectly because I assumed all bolts were the same type (DIN) and that the Kioti loader parts diagram had the wrong diameters. The four front bolts had 22mm heads and the four back ones 19mm heads. So (incorrectly sticking with the DIN type) I assumed the back ones were 12mm diameter. I now think they are 14mm diameter bolts (with the JIS 19mm head) as labelled in the parts list.

I've attached a Metric Bolt Head/Wrench Size table.

I just went to check my dk45, and all 9 loader mount bolts are the same. Its a new tractor, so i guess they changed some stuff.

 

[SixHoeBob]

I have yet to find any torque settings on my Vise-Grips. For lack of a better system,I try to tighten all bolts to 1/4 turn before breaking.

 

[kco]

I just went to check my dk45, and all 9 loader mount bolts are the same. Its a new tractor, so i guess they changed some stuff.

The KL401 loader found on the DK40/45/50's is a bit different than the DK35's KL351. The main front 4 KL351 M14 bolts are longer than those used on the KL401. Perhaps the longer bolts are not available as JIS so they use ISO bolts.

I was in town last night and checked a DK50 on the dealer's lot and saw all the bolts are the same type JIS as you mention. I should have trusted the Kioti Loader manual parts list instead of incorrectly assuming bolt diameters from the head sizes. But I don't have a lot of faith in the manuals.

Strangely, the manual's torque table shows torques for only ISO type bolts that don't exist on the KL401 and are only the two sets of the front four bolts on the KL351. Even in this table they label the bolt as 10.7 instead of the correct 10.9.

Anyhow, my confusion is cleared up now.

 

[grsthegreat]

The KL401 loader found on the DK40/45/50's is a bit different than the DK35's KL351. The main front 4 KL351 M14 bolts are longer than those used on the KL401. Perhaps the longer bolts are not available as JIS so they use ISO bolts.

I was in town last night and checked a DK50 on the dealer's lot and saw all the bolts are the same type JIS as you mention. I should have trusted the Kioti Loader manual parts list instead of incorrectly assuming bolt diameters from the head sizes. But I don't have a lot of faith in the manuals.

Strangely, the manual's torque table shows torques for only ISO type bolts that don't exist on the KL401 and are only the two sets of the front four bolts on the KL351. Even in this table they label the bolt as 10.7 instead of the correct 10.9.

Anyhow, my confusion is cleared up now.

good point. i think i will try and get a proper torque table from Fasteners inc.... just to be sure. by the way....does anyone here use torque sticks here....the things you can place on the end of a impact wrench to set torques??

 

[Transit]

I would never use torque sticks, use a 6 point socket and a half inch drive click type torque wrench. For smaller bolts use a 3/8 inch drive wrench, I also like to use ant seize compound and set the torque to the lower value in the range.

 

[kco]

good point. i think i will try and get a proper torque table from Fasteners inc.... just to be sure. by the way....does anyone here use torque sticks here....the things you can place on the end of a impact wrench to set torques??

I've attached the torque table my dealer sent me for the the JIS 7T and 9T bolts.

 

[kco]

I would never use torque sticks, use a 6 point socket and a half inch drive click type torque wrench. For smaller bolts use a 3/8 inch drive wrench, I also like to use ant seize compound and set the torque to the lower value in the range.

I'm glad I did my 50 hour service myself as it forced me to learn more about the tractor and need to regularly torque the loader bolts. Besides, it was a good excuse to purchase a 1/2" torque wrench. --which was on sale for 60% off.:thumbsup:

The Kioti loader manuals specify the bolts should be torqued every 25 hours but that is not mentioned in the tractor's Owner's Manual.

I used the average of the minimum and maximum values to torque the bolts.

 

[grsthegreat]

I've attached the torque table my dealer sent me for the the JIS 7T and 9T bolts.

thank you

 

[sriddle1ny]

I've attached the torque table my dealer sent me for the the JIS 7T and 9T bolts.

Kco,

I feel a Primal Scream Building Those Sten-ken Bolts !!:shocked:

I recently purchased an '04 JD 790, it has a Yanmar Engine MODEL: 3TNV82A-LJNT (so-far-so-good). Since I've just completed all the fluid and filter changes I thought I'd tackle the Thermostat remove and replace task. :cool2:

The on-line JD Parts Catalog excerpt (attached) you'll see PN: 19M7867 (Key # 6) for (2) Bolts attaching the COVER to the top of the water pump assembly. There's usually some additional information in the REMARKs Column like the diameter and length, this time however nothing.

So off to the internet search and I found a JD1200A (attached) using the same PN (Key # 7) and the REMARKS Column indicates: M8 X 25 (HS, HEAD MARKED 10.9)?GREAT ! :thumbsup:

With that information and my handy-dandy Metric Bolt and Cap Screw Torque reference (attached) , the Torque Value should be 23.5 ft-lb Lubricated or 29.5 ft-lb Dry?. BETTER YET, PRETTY SIMPLE ! :thumbsup:

Just when I thought everything was peachy keen I noticed a small detail, the (2) Flange Bolt Hex Heads in question were marked with "7" (picture attached)

So off I went through the forums and found your thread with the handy-dandy reference guide for Japanese Standards (BoltTorquesFor_7Tand9T_Bolts) attached. I found the "7" hex head marking column and HUH ? Torque indicates "17.4-20.2 lbf-ft" and so I'm reaching for an answer, is the John Deere Replacement Part to the same spec the Yanmar "7" Bolt was made to.........


ANY SUGGESTION WOULD BE APPRECIATED THANKS...........

 

[RoyJackson]

I think the torque values in red bolded font should be Newton-Meters, not ft-lbs. Suggest you reread the columm headers of the conversion chart and I think you'll see what I mean.

Kco,

I feel a Primal Scream Building Those Sten-ken Bolts !!:shocked:

I recently purchased an '04 JD 790, it has a Yanmar Engine MODEL: 3TNV82A-LJNT (so-far-so-good). Since I've just completed all the fluid and filter changes I thought I'd tackle the Thermostat remove and replace task. :cool2:

The on-line JD Parts Catalog excerpt (attached) you'll see PN: 19M7867 (Key # 6) for (2) Bolts attaching the COVER to the top of the water pump assembly. There's usually some additional information in the REMARKs Column like the diameter and length, this time however nothing.

So off to the internet search and I found a JD1200A (attached) using the same PN (Key # 7) and the REMARKS Column indicates: M8 X 25 (HS, HEAD MARKED 10.9)?GREAT ! :thumbsup:

With that information and my handy-dandy Metric Bolt and Cap Screw Torque reference (attached) , the Torque Value should be 23.5 ft-lb Lubricated or 29.5 ft-lb Dry?. BETTER YET, PRETTY SIMPLE ! :thumbsup:

Just when I thought everything was peachy keen I noticed a small detail, the (2) Flange Bolt Hex Heads in question were marked with "7" (picture attached)

So off I went through the forums and found your thread with the handy-dandy reference guide for Japanese Standards (BoltTorquesFor_7Tand9T_Bolts) attached. I found the "7" hex head marking column and HUH ? Torque indicates "17.4-20.2 lbf-ft" and so I'm reaching for an answer, is the John Deere Replacement Part to the same spec the Yanmar "7" Bolt was made to.........


ANY SUGGESTION WOULD BE APPRECIATED THANKS...........

 

[sriddle1ny]

Hey Roy, You're up already..........

I see I forgot to include the handy-dandy reference, sorry about that............

 

[RoyJackson]

Hey Roy, You're up already..........

I see I forgot to include the handy-dandy reference, sorry about that............

Actually, got home from work about an hour ago...

Do some more research...although there appears to be a contradiction, I don't think there is.
One chart is listing a minimum torque spec, the other a maximum. Also, the bolt coating and/or alloy can have a different recommended torque. When you do your research, you'll see more values for a given size.

Here's another chart, BTW. Metric fasteners are about halfway down the chart.

 

[John_in_TN]

I may have missed your reason for not using the originally spec'd JD part number, but when I search for that p/n on JD Parts I find the following info which includes specs and my local store has 31 in stock for $0.65 each:

Part Details

Part Number:

19M7867
Part Price:0.65 USD
On Hand:

31 Check Other Stores
Description:SCREW, FLANGED, METRIC
All Makes Parts from John Deere Where Used

EnglishMetric

Specification
Weight0.02 LBS 0.01 Kg
Thread Size0.315 IN
Thread Pitch0.049 IN
Length0.984 IN
Thread Length0.837 IN
Flange Diameter0.709 IN
Head Height0.319 IN
Material or Grade10.9
Drive Size0.512 IN
Finish B Note

Part Diagram

 

[RoyJackson]

I may have missed your reason for not using the originally spec'd JD part number, but when I search for that p/n on JD Parts I find the following info which includes specs and my local store has 31 in stock for $0.65 each:

There were three engines used in the 790 during it's production run...the bolt sriddle1ny specified may have been the one spec'd for his engine.

I suspect the one you quoted is for the current engine.

 

[John_in_TN]

Roy, according to his (sriddle1ny) post he identified 19M7867 as the correct part from JD Pars online for his application, but because he didn't find the specs for that p/n, he searched online and found a second p/n. It wasn't clear to me why he abandoned the original p/n.
I was just trying to point out that JD Parts does give the specs for 19M7867 and it appears to be available from JD.

"The on-line JD Parts Catalog excerpt (attached) you'll see PN: 19M7867 (Key # 6) for (2) Bolts attaching the COVER to the top of the water pump assembly. There's usually some additional information in the REMARKs Column like the diameter and length, this time however nothing. "

 

[RoyJackson]

Roy, according to his (sriddle1ny) post he identified 19M7867 as the correct part from JD Pars online for his application, but because he didn't find the specs for that p/n, he searched online and found a second p/n. It wasn't clear to me why he abandoned the original p/n.
I was just trying to point out that JD Parts does give the specs for 19M7867 and it appears to be available from JD.

"The on-line JD Parts Catalog excerpt (attached) you'll see PN: 19M7867 (Key # 6) for (2) Bolts attaching the COVER to the top of the water pump assembly. There's usually some additional information in the REMARKs Column like the diameter and length, this time however nothing. "

I'll take your word on that.