Size 1 1/2, HS 220-18 Aircraft Hot Rolled Normalized and Tempered Alloy

HS 220-18 is a low carbon, high silicon, chromium nickel molybdenum alloy steel. It was one of the first grades developed in the high strength class, combining strength with toughness and ductility. It has relatively high impact resistance because of its low notch sensitivity at the high hardness at which this alloy is commonly used. It is available as a basic electric furnace air melt and vacuum degassed product to meet the high aircraft quality standards of AMS 2301. In addition, this alloy is produced as Special Aircraft Quality to insure transverse ductility and toughness.

MIL-S-7108 - AMS 6418 - AMS 2301 - DMS 1841

Color Marking: Ends painted Purple with Pink Stripe

Physical Conditions E
Surface Condition 1

Stock Lengths 20' Approx.

Unit of Measure

Specifications

Estimated Weight per Foot	N/A 6.014 lb
Estimated Weight 20-Ft. Bar	N/A 120.3 lb

Analysis

N/A Carbon .23/.28
Manganese 1.20/1.50
Phosphorus .025 Max.
Sulphur .025 Max.
Si. 1.30/1.70
Cr. .20/.40
Ni. 1.65/2.00
Mo. .35/.45

Applications

N/A Intended for use in the manufacturing of parts and components requiring high strength and good ductility with relatively high impact strength at room and lower temperatures.

Mechanical Properties

N/A Response to heat treatment and transverse ductility of this alloy are assured by tension tests performed on samples taken from the mid-radius and center location of the top and bottom of the first, middle, and last ingots of a heat. Results of the center tests are for information only. Results of the mid-radius tests after heat treatment are:
Tensile - 220/245,000 psi
Yield - 185,000 psi Min
Elongation in 2" - 5% Min.
Reduction of Area Average All Tests- 20% min
Reduction of Area Lowest Single Test- 15% min
V-Charpy Ft. Lbs. 12 Min.

Hardening

N/A End-quench hardenafaility values are Rockwell "C" 47 minimum at 8/16" and Rockwell "C" 45 minimum at 24/16".

Heat Treating

N/A Normalize—1725°F
Austenitize—1600°F
Quench—Oil, 140°F maximum
Temper—550 "7575° F