Material & Grade Guide
Grade and material decide how much load a fastener carries and how long it survives its environment. This guide covers every material class we stock: low carbon through Grade 8, structural ASTM specifications, metric property classes, the full stainless range, non-ferrous alloys, tool steels, and polymer hardware.
Low Carbon Steel and Grade 2
Ductile, economical, easy to form, near 74,000 psi tensile in smaller diameters. Almost always plated, since bare low carbon steel has no corrosion resistance of its own.
Grade 5, Medium Carbon (SAE J429 / ASTM A449)
Quenched and tempered to roughly 120,000 psi through 1 inch. The dependable step up from low carbon for automotive, machinery, and equipment joints.
Grade 8, Medium Carbon Alloy (SAE J429)
Quenched and tempered alloy near 150,000 psi. Specified where clamp load and shear run high: structural work, trailers, and heavy equipment.
Case Hardened and Through Hardened Steel
Case hardening puts a hard skin on a tough core for self-drilling, self-tapping, and thread cutting screws. Through hardening runs 50 to 62 HRC across the full section for hardened washers, dowel pins, and shoulder bolts.
Alloy 6150 and Alloy 8650
Chromium vanadium and chromium nickel molybdenum alloys chosen for fatigue life and toughness in spring pins, retaining hardware, and select high-strength products.
ASTM A307 Grade A and Grade B
General-purpose structural bolts in low carbon steel near 60,000 psi. Grade A covers machine and flange bolting; Grade B is capped at both ends for cast iron pipe flanges.
ASTM A325 and A490 Type 1
A325 heavy hex runs near 120,000 psi for steel-to-steel connections. A490 steps to 150,000 psi for slip-critical joints and ships plain rather than hot dip galvanized to avoid embrittlement.
ASTM A354 Grade BD
Quenched and tempered alloy studs, rod, and bolts near 150,000 psi. The answer when a job needs Grade 8 strength in a diameter or length hex cap screws do not reach.
ASTM F1554 Grade 36 and Grade 55
Anchor bolt steel for concrete embedment. Grade 36 is weldable low carbon bar near 58,000 psi; Grade 55 steps to roughly 75,000 psi, including the S1 weldable supplement.
Structural Nuts and Washers
A563 Grade A pairs with A307, Grade C with A325, and heavy hex Grade DH with A325 and A490. F436 washers are through hardened to 38 to 45 HRC. Locknut Grades A, C, and G match Grade 2, 5, and 8 bolts.
ASTM A193 Grade B7
Chromium molybdenum alloy studs and threaded rod, quenched and tempered near 125,000 psi. The default for flange bolting in refining, petrochemical, steam, and process piping.
ASTM A194 Grade 2H, A194 and SA194
The heavy hex nut that runs on B7 studs, quenched and tempered to 24 HRC minimum. The SA prefix marks the ASME pressure vessel version of the same nut specification.
Property Class 4.6
Low carbon metric steel at 400 MPa tensile and 240 MPa yield. The metric answer to general-purpose inch hardware, used where load is light and cost leads.
Property Class 8.8
Quenched and tempered medium carbon at 800 MPa tensile and 640 MPa yield. Roughly Grade 5, and the most stocked class across DIN 931, DIN 933, DIN 960, ISO 4014, and ISO 4017.
Property Class 10.9
Alloy steel at 1040 MPa tensile and 940 MPa yield, landing between Grade 5 and Grade 8. Common on DIN 912 socket, DIN 6921 flange, DIN 7984, and ISO 7380 button head products.
Property Class 12.9
The highest common metric class at 1220 MPa tensile and 1100 MPa yield. Standard on DIN 912 socket head cap, DIN 7991 flat socket, ISO 7380, and ISO 7379 shoulder screws.
Class 45H Set Screws and Nut Classes 4 to 10
Metric set screws are hardness rated at 45 HRC minimum across DIN 913 to DIN 916 and ISO 4026 to 4029. Nut classes match the bolt they run on: Class 4 and Class 6 for lower grade work, Class 8 on 8.8, Class 10 on 10.9, so an overloaded joint stretches the bolt instead of stripping threads.
Stainless 18-8, 304, and A2
Three names for one austenitic family at roughly 18 percent chromium and 8 percent nickel. Strong general corrosion resistance, largely non-magnetic, and our highest volume stainless.
Stainless 316 and A4
Marine-grade austenitic stainless. Added molybdenum gives far better resistance to chlorides, salt spray, and process chemicals, making it the call for coastal and offshore work.
Metric Classes A2-70, A4-70, and A4-80
The strength side of metric stainless. The 70 class reaches 700 MPa tensile and the 80 class 800 MPa, so a print calling A4-80 wants 316 chemistry plus a cold worked strength level.
Stainless 305
A low work hardening austenitic grade with higher nickel. It cold forms, spins, and deep draws without cracking, which is why it replaces 304 on severely formed parts.
Stainless 410, 416, and 420
Hardenable martensitic grades. 410 points self-drilling and self-tapping screws, 416 adds sulfur for free machining on turned parts, and higher carbon 420 forms the drill point on bi-metal screws.
Stainless 430 and the 400 Series
430 is ferritic, magnetic, and nickel free, serving trim and appliance hardware at lower cost. The 400 series as a whole trades some corrosion resistance for hardness and magnetism.
Inch Stainless Specifications
F593 covers inch stainless bolts in alloy groups 1 and 2, with condition CW near 100,000 psi. A193 B8 is 304 and B8M is 316 for studs; A194 Grade 8 and 8M are the matching nuts, keeping one chemistry through the joint.
Brass
Copper and zinc, typically C360. Corrosion resistant, non-magnetic, non-sparking, and conductive, which is why it leads in electrical hardware, plumbing, and decorative work.
Silicon Bronze 651 and Phosphor Bronze
C65100 silicon bronze outlasts brass and most stainless in saltwater and will not stain hardwood, the traditional pick for boats, docks, and exterior timber. Phosphor bronze carries spring washers on fatigue life.
Aluminum 5056 and 6061-T6
5056 is the magnesium bearing rivet and rivet nut alloy. 6061-T6 is heat treated structural aluminum near 45,000 psi, used where steel would add weight or invite galvanic attack.
Zinc Alloy, Die Cast, and Lead Alloy
Cast zinc holds tight dimensions straight from the die for toggles, drop-ins, and expansion anchors. Lead sleeves in lag shields deform against the hole to grip masonry.
Cast Iron and Class 30 Grey Iron
Grey iron near 30,000 psi with excellent damping and machinability. Stocked in clamp bodies, brackets, and hardware where rigidity beats tensile numbers.
High Speed Steel and Cobalt
M2 high speed steel holds an edge at temperatures that soften carbon steel, the baseline for jobber drills and taps. Adding 5 to 8 percent cobalt (M35, M42) cuts stainless, titanium, and work hardening alloys.
Carbide Tipped and Solid Carbide
A brazed carbide tip on a steel body handles masonry, concrete, and abrasive stock. Solid tungsten carbide runs the full body for maximum rigidity and edge life on hardened material.
Nylon, Plastic, PVC, and Polycarbonate
Nylon serves locking inserts and set screw tips that grip without marring. Molded plastic and PVC anchor bodies expand as the screw drives. Polycarbonate adds impact resistance where a part has to take a hit.
Polypropylene
Chemically resistant and light, with good fatigue life in living hinges. Common in containment, washdown, and corrosive settings where metal hardware would not survive.
| Grade / Class | Material | Strength | Typical Use |
|---|---|---|---|
| Grade 2 | Low carbon steel | ~74 ksi | General hardware |
| Grade 5 / A449 | Medium carbon, Q and T | ~120 ksi | Automotive, machinery |
| Grade 8 | Medium carbon alloy, Q and T | ~150 ksi | Structural, heavy equipment |
| A307 Grade A / B | Low carbon steel | 60 to 100 ksi | General structural, pipe flange |
| A325 Type 1 | Medium carbon, Q and T | ~120 ksi | Steel structural connections |
| A490 Type 1 | Alloy steel, Q and T | ~150 ksi | Slip-critical structural |
| A354 Grade BD | Alloy steel, Q and T | ~150 ksi | Studs, rod, long lengths |
| F1554 Grade 36 / 55 | Low carbon bar | 58 to 95 ksi | Anchor bolts |
| A193 B7 | Chromium molybdenum alloy | ~125 ksi | Flange studs, high temperature |
| Class 4.6 | Low carbon steel | 400 MPa | Light duty metric |
| Class 8.8 | Medium carbon, Q and T | 800 MPa | General metric hex and flange |
| Class 10.9 | Alloy steel | 1040 MPa | Socket, flange, button head |
| Class 12.9 | Alloy steel | 1220 MPa | Socket head cap, flat socket |
| Class 45H | Alloy set screw steel | 45 HRC min | Metric set screws |
| Nut Class 4 / 6 / 8 / 10 | Carbon and alloy nut steel | Matched to bolt | Metric nut side |
| 18-8 / 304 / A2 | Austenitic stainless | ~70 to 90 ksi | Indoor, outdoor, wet |
| 316 / A4 | Austenitic stainless | ~70 to 90 ksi | Marine, coastal, chemical |
| A2-70 / A4-70 / A4-80 | Cold worked stainless | 700 to 800 MPa | Metric stainless hardware |
| 410 / 416 / 420 | Martensitic stainless | High when hardened | Self-drilling, machined, points |
| 430 | Ferritic stainless | Moderate | Trim and appliance hardware |
| Silicon Bronze 651 | Copper alloy | Moderate | Marine, docks, exterior timber |
| Brass C360 | Copper zinc alloy | Low to moderate | Electrical, plumbing, decorative |
| Aluminum 6061-T6 | Heat treated aluminum | ~45 ksi | Light structural, panel work |
Browse Grades We Stock
Need Help Picking a Grade?
Call (714) 790-4042 or contact our team for help matching the right grade and finish to your application.
Contact Our TeamRequest A Quote