<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class AddThreadsColumnToServersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('servers', function (Blueprint $table) {
            $table->string('threads')->nullable();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('servers', function (Blueprint $table) {
            $table->dropColumn('threads');
        });
    }
}

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class AddThreadsColumnToServersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('servers', function (Blueprint $table) {
            $table->string('threads')->nullable()->after('cpu');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('servers', function (Blueprint $table) {
            $table->dropColumn('threads');
        });
    }
}

Move threads column to the
Move threads column to the 

Put column after CPU, not at the end.