Just got off the phone with George at CV Unlimited. I had emailed them this week to get replacement "guts" since I've yet to break the Newfield bell but seem to be adept at disintegrating the sleeve/cage/balls.

They are in the process of reworking some things, largely because of the success of the Longfields (which he's followed closely). According to George, the Longfield is brought to a Rockwell of 50, which while great for strength, sacrafices longevity and wear. He is re-working the corresponding Newfield part to a Rockwell 48 rating, thinking this may offer a better compromise between strength and wear.

He plans to have these ready in a week or two, and (with a reminder email) said he would send me out a couple sets to try out....just in time for the BHCC, which should give them a decent workout.

(I'm a Rockwell/physics idiot...hopefully someone smarter than me can speak up with better tech info)

Only George would question the success of the Longfield by changing something that has been so increadibly successful.

I don't know about you, but he should also be paying attention to the price of these things too.

FYI, of the 5 I broke, none of the inner cages went :confused:

Oh well, I would sacrifice longevity in a HEARTBEAT for durability.

Shit, who actually WEARS OUT a Birfiled on a trail rig?

I think it is real cool of George to send you some of the new one though. He has always had increadible customer service.

If I understand the Rockwell hardness scale correctly the higher the number the softer the media, rockwell is tested by dropping a hardend pin with a known weight on the media being tested and then measuring the depth of the dent to get the hardness, a simple but effective means to get hardness measurment.

-Scott

Ok, I got bored and looked it up!!


Rockwell A-Scale Hardness
Brale indenter, 60 kgf load




Symbol: HRA

The Rockwell Hardness Test presses a steel or diamond hemisphere-conical penetrator against a test specimen and measures the resulting indentation depth as a gage of the specimen hardness. The harder the material, the higher the HR reading.

In the test, a minor load (10 kgf) is first applied, and the test dial (measuring the indention depth) is reset to zero. Then a major load (60, 100, or 150 kgf) is applied to create the full indention. The major load is reduced back to the minor load, and the indention depth measurement is taken.

The penetrator is usually 1/16 inch in diameter, although larger diameters (such as 1/8 inch) may be used for softer metals. Choosing the proper penetrator and the corresponding load requires experience. Some commonly used combinations are summarized below:

Scale Condition Application
A Brale indenter
60 kgf load Thin, hard sheet materials, such as tungsten carbide.
B 1/16 in diamond ball
100 kgf load Medium/low hard materials, such as annealed carbon steels.
C Brale indenter
150 kgf load Materials harder than HRB 100.
D Brale indenter
100 kgf load Case-hardened materials.
F 1/16 inch Brale indenter
60 kgf load Soft materials, such as bearing metals.
N 1/16 inch Superficial Brale indenter
15, 30, or 45 kgf load Unhardened materials, such as metals softer than hardened steel or hard alloys, or where shallow indentations are desired.
T 1/16 inch diamond ball
15, 30, or 45 kgf load Unhardened materials, such as metals softer than hardened steel, or where shallow indentations are desired.




Convert HRA
(suggested range: 59 ~ 86)

HRA 72 approximately* =

Hardness
Symbol Amount Name Suggested
Range
HB (3000) 401 Brinell 10 mm Standard 3000 kgf 80~445
HB (500) >> Brinell 10 mm Standard 500 kgf 89~189
HB (Tungsten 3000) 401 Brinell 10 mm Tungsten 3000 kgf 80~620
HB (Indentation) 3.06 mm Brinell Indentation 6~2
HK 443 Knoop 97~920
HM 4 Mohs 1~10
HRB >> Rockwell B-Scale 41~100
HRC 43 Rockwell C-Scale 19~69
HRD 58 Rockwell D-Scale 39~77
HRF >> Rockwell F-Scale 88~100
HR-15N 82 Rockwell Superficial 15N 69~94
HR-15T >> Rockwell Superficial 15T 77~93
HR-30N 62 Rockwell Superficial 30N 41~85
HR-30T >> Rockwell Superficial 30T 53~82
HR-45N 47 Rockwell Superficial 45N 19~76
HR-45T >> Rockwell Superficial 45T 28~71
HS 57 Shore Scleroscope 17~97
Approx. TS 1389 MPa Tensile Strength (Approx.) 390~2450
HV 424 Vickers 20~1800


Legend
<< The hardness value is below the acceptable range of the particular hardness scale.
>> The hardness value is above the acceptable range of the particular hardness scale.
### The hardness value is near the limit (within 15%) of the acceptable range of the particular hardness scale.

* The many hardness tests listed here measure hardness under different experimental conditions (e.g. indenters made in different sizes, shapes, and materials, and applied with different loads) and reduce their data using different formulae. As a result, there is NO direct analytic conversion between hardness measures. Instead, one must correlate test results across the multiple hardness tests.
This calculator is based on hardness data compiled from ASM Metals Reference Book 3rd ed, published by ASM International, and Machinery's Handbook 25th ed, published by Industrial Press. The calculator curve-fits multiple hardness data onto a common polynomial basis and then performs an analytic conversion. The accuracy of the conversion depends on the accuracy of the provided data and the resulting curve-fits, and on the valid ranges spanned by the different hardness tests. Converted hardness values should be used for comparative purposes only.

Originally posted by wngrog
I don't know about you, but he should also be paying attention to the price of these things too.

True!!

I think it is real cool of George to send you some of the new one though. He has always had increadible customer service.

I'll second that...his customer service is EXCELLENT, although it seems that some of the people that work under him have a hard time sending the right parts the first time.