Delrin 100 vs 150: Which Grade for Machining and Molding?

Visual comparison of Delrin 100 molding grade pellets and a molded clip vs. a Delrin 150 extruded rod and a CNC machined precision part.

Delrin 100 and Delrin 150 are both high viscosity acetal homopolymers (POM-H), and their datasheets list the same melt flow: 1.9 cm³/10 min (ISO 1133, 190 °C / 2.16 kg) [1] [2]

What differs is what each was developed for.

Delrin 100 is described as a high viscosity grade for easy to fill molds [2].

Delrin 150 is a nucleated grade developed for extrusion [1] and it is the POM-H grade that Trident Plastics and Sterling Plastics list for rod and plate [4] [6].

Quick answer

Machining from rod, plate or sheet: start with a Delrin 150 stock shape, and design from the stock shape datasheet, not the resin datasheet.
Injection molding: start with the 100 family, then pick the toughness and flow variant that fits your mold.
Thick stock, large diameters, or sealing/wetted parts: check centerline porosity before you worry about the grade number.

What the Datasheets Say: Matched Resin Data

Delrin 100 NC010 is described as a high viscosity homopolymer for easy to fill molds, with a balance of toughness and strength [2].

Delrin 150 NC010 is described as designed for extrusion, with low die deposit, good thermal stability, and enhanced crystallization for low porosity [3].

The table below puts both on the same ISO test methods.

Property (resin, 23 °C)	Delrin 100 NC010	Delrin 150 NC010	Test method
Melt volume-flow rate, 190 °C / 2.16 kg	1.9 cm³/10 min [2]	1.90 cm³/10 min [1]	ISO 1133
Tensile modulus	2,900 MPa [2]	3,100 MPa [1]	ISO 527
Tensile stress at yield	71 MPa [2]	73.0 MPa [1]	ISO 527
Tensile strain at yield	26 % [2]	22 % [1]	ISO 527
Notched impact	15 kJ/m² (Charpy) [2]	10 kJ/m² (Izod) [1]	ISO 179/1eA vs ISO 180/1A: different tests, not comparable
Tensile creep modulus, 1,000 h	1,600 MPa [2]	Not on the free datasheet	ISO 899-1
Processing methods listed	Injection molding (easy-to-fill molds) [2]	Extrusion, profile and sheet extrusion, injection molding [1]	n/a

The two columns come from different databases (Material Data Center for 100, Delrin USA/UL Prospector data sheet for 150). Confirm against the current Delrin USA datasheet for the lot you buy.

How to read it:

On resin data, 150 is about 7% stiffer and about 3% higher in yield stress than 100. That is a small gap, and it sits inside the normal spread between lots and test labs.

The impact row is the trap:15 kJ/m² (Charpy) and 10 kJ/m² (Izod) are different tests on different notch setups, so neither number says one grade is tougher.

If impact or creep decides the job, ask the supplier for the exact grade values and test the part.

Machining: What You Are Actually Buying

When you machine Delrin, you are buying an extruded stock shape, not resin pellets.

Delrin 150 NC010 stock shapes are listed in rod from 0.187 to 10.00 in diameter and plate from 0.031 to 5.00 in thick, with plate sizes of 24 × 48 and 48 × 120 in [4].

Delrin 150 is also the base resin in the 13% PTFE “AF blend” rod and plate, a 2:1 blend of 20% PTFE-filled Delrin and unfilled 150 [16].

Stock-Shape Data (Delrin 150 NC010, Natural, ASTM Methods)

Property	Value	Method
Density	1.41 g/cm³	n/a
Tensile modulus	350,000 psi (about 2,410 MPa)	ASTM D638
Tensile strength at yield	11,000 psi (about 76 MPa)	ASTM D638
Tensile elongation at break	25 %	ASTM D638
Flexural modulus	470,000 psi (about 3,240 MPa)	ASTM D790
Shear strength	9,800 psi (about 68 MPa)	ASTM D732
Notched Izod impact	2 ft·lb/in (about 107 J/m)	ASTM D256
Water absorption, 24 h / saturation, 73 °F	0.25 % / 0.9 %	ASTM D570
Standards and compliance listed	ASTM D6778-20 POM0111; ASTM D6100-17 S-POM0111; FDA 21 CFR 177.2480; NSF/ANSI 51 and 61	Distributor listing

Source: Trident Plastics Delrin 150 NC010 extruded shapes data sheet [4]. Metric values are our unit conversions.

Do not mix the two tables: The stock shape tensile modulus (about 2,410 MPa, ASTM D638) is lower than the resin value (3,100 MPa, ISO 527).Different test method, different specimen, different material form.

For a machined part, use the stock shape numbers, and get the certificate for the lot. Even the same distributor’s natural and black 150 sheets differ: elongation is listed as 25% for natural [4] and 40% for black,[5] and the black listing shows no FDA or NSF line.[5]

Centerline Porosity: The Check That Matters More Than the Grade Number

Homopolymer acetal stock can have a low density center, especially in large cross sections. The Delrin 150 shape data sheets say so directly [4].

Trident’s acetal comparison guide calls it the biggest difference between homopolymer and copolymer shapes, most prominent in thick slab and large diameter rod, and attributes it to shrinkage [7].

Boedeker describes it as interconnected micro porosity of about 100 to 150 microns in homopolymer stock [8].

The 150 resin is marketed with enhanced crystallization for low porosity [3] but that does not remove the effect in thick shapes.

One distributor states that Delrin 150 is not USP Class VI compliant because of it [6].

The practical question is whether the center of the stock ends up inside your finished part.

Finished part	Is the center in the part?	What to do
Bored bushing or sleeve	Usually no, the bore removes it	Low concern; confirm bore diameter clears the affected zone
Solid shaft, gear blank, disc	Yes	Ask the supplier for a porosity statement for that diameter or thickness
Part that holds pressure, fluid or a seal face	Yes, and it matters most	Treat the center as a possible leak path; require a porosity statement, or consider copolymer stock

Copolymer acetal (POM-C) stock is reported to have little or no centerline porosity [9] at the cost of some strength and stiffness.

Homopolymer is roughly 10 to 15% higher [8] If your load case allows it.

See our detailed guide on Delrin vs. Acetal (POM-H vs. POM-C).

Molding: Start With the 100 Family

For injection molding, Delrin 100 is the datasheet described easy to fill high viscosity grade [2].

The 100 family is wider than one grade, and the property spread inside it is far larger than the 100 versus 150 gap

Grade	Positioning	Tensile modulus (ISO 527)	Notched Charpy, 23 °C
Delrin 100 NC010	High viscosity, strength and toughness balance	2,900 MPa [2]	15 kJ/m² [2]
Delrin 100ST NC010	Super-toughened high viscosity	1,400 MPa [11]	90 kJ/m² [11]

If a molded part must survive impact, the toughened 100 family grades are the lever, not 100 versus 150.

If a high viscosity grade fills your geometry poorly, Delrin also offers medium viscosity grades such as the 500 series [15]

Neither grade is locked to one process. The 150 data sheet lists injection molding with a melt temperature of 210 to 220 °C, and extrusion at 195 to 205 °C [1].

Other 100 family grades, 100T and 100TL, are listed for profile and sheet extrusion.[12] [13]

Cost: Utilization and Tooling Breakeven

We do not publish resin or stock prices because they move by supplier, size and quantity.

Two calculations you can run with your own quotes are more useful.

Material utilization for a machined part

Utilization = finished volume ÷ stock volume consumed.

Illustrative example (assumes 1¾ in rod is stocked):

A solid Ø40 × 30 mm part cut from Ø44.45 mm rod with a 3 mm facing and part off allowance.

Finished volume: about 37,700 mm³, or about 53 g at 1.41 g/cm³ [4].
Stock slug (33 mm long): about 51,200 mm³, or about 72 g.
Utilization: about 74%, with about 19 g removed as chips per part.

Multiply the stock mass by your quoted price per kilogram to get material cost per part, and compare stock sizes by utilization, not by price per rod.

This part also keeps its center, so the porosity check above applies to it.

Molding versus machining breakeven

Breakeven quantity = mold cost ÷ (machined cost per part − molded cost per part), with both per part costs excluding tooling.

Below that quantity, machining from stock usually wins; above it, molding does.

Quick Decision Guide

Situation	Start with	Check before ordering
CNC part from rod or plate, bored or thin-walled	Delrin 150 stock shape	Stock size and the certified ASTM D6100 edition
Solid part from large rod or thick plate	Delrin 150 stock, or POM-C if the load allows	Porosity statement for that diameter or thickness
Food, potable water or medical adjacent	The exact listed compliant grade	Compliance for the specific form and color; FG150 is the food contact resin grade [14]
High volume molded part	Delrin 100 family	Mold fill, toughness variant, tooling breakeven
Impact loaded molded part	100T or 100ST class	Stiffness loss against impact gain (table above)
Sliding or wear part	PTFE-filled or AF-blend stock	Friction and wear data for that exact stock

FAQ

Is Delrin 150 stronger than Delrin 100?

Not in a way that matters for selection.
On ISO resin data, 150 is about 7% stiffer and 3% higher in yield stress (tables above).
The stock shape numbers are measured by a different method and are not comparable with the 100 resin values.

Can Delrin 100 be extruded, and can Delrin 150 be injection molded?

Yes to the second: the 150 data sheet lists injection molding [1] For the first, the 100NC010 sheet describes molding use, [2] while 100T and 100TL are listed for profile and sheet extrusion.[12] [13]
If you need extruded 100-family stock, ask the producer for the exact grade.

Is Delrin 150 food safe or USP Class VI?

The natural 150 stock listing shows FDA 21 CFR 177.2480 and NSF/ANSI 51 and 61 [4].
The black listing shows neither [5].
One distributor says 150 is not USP Class VI compliant because of centerline porosity [6].
Compliance is grade, form and color specific, so require the certificate.

Does Delrin 150 eliminate centerline porosity?

No. The 150 shape data sheets still warn about it in large cross sections [4]. See the porosity section above for what to ask your supplier.

Related Guides

Sources

All sources last checked October 6, 2026. Datasheet values are typical values, not specifications.

Last Reviewed: October 2026

Usama Ayub

Usama Ayub is the founder of PlasticSpec and a polymer manufacturing engineer with eight years of hands-on industrial experience in PET, PA6, and PA66 fiber and filament yarn production. He writes material property and selection guides for Delrin, Nylon, PEEK, PTFE, UHMW, Polycarbonate, and ABS.

Delrin 100 vs. 150